Rev. 1.0 8/10 Copyright © 2010 by Silicon Laboratories CP2400/1/2/3
CP2400/1/2/3
128/64 SEGMENT LCD DRIVER
LCD Driver
Controls up to 128 segments (48-pin packages) or
64 segments (32-pin package)
Supports static, 2-mux, 3-mux, and 4-mux displays
On-chip bias generation with internal charge pump
Low power blink capability
GPIO Expander
Expands GPIO count by up to 36 pins (48-pin packages)
or 20 pins (32-pin package)
GPIO pins may be configured to push-pull or open-drain
outputs with two drive levels. GPIO may also be used as
digital inputs (CP2400/1/2/3 pullups included)
Port Match Capability can wake up host controller using
interrupt pin
5 V Tolerant I/O
Real Time Clock, SmaRTClock
Precision time keeping with 32.768 kHz watch crystal;
self-oscillate mode requires no external crystal; accepts
external 32 kHz CMOS clock
36-hour programmable counter with wake up alarm
Can wake up the host controller using interrupt pin
Low power (<1.5 µA)
256 Bytes RAM
General purpose RAM expands the memory available to
host controller.
16-bit Timers
Two general purpose 16-bit timers
Clock Sources
20 MHz Internal oscillator
Can be clocked from an external CMOS clock
Digital Bus Interface
4-wire SPI Interface operates up to 2.5 Mbps with
synchronous external clock or up to 1 Mbps with internal
clock (CP2400/2 only).
2-wire SMBus/I2C Interface operates up to 400 kHz with
internal clock (CP2401/3 only).
Dedicated RST and INT pins.
Optional CLK pin can be used as a CMOS clock input.
Optional PWR pin (SMBus/I2C devices only) places the
device in a low power mode. SPI devices use the NSS
pin to place the device in a low power mode.
Low Power
1.8–3.6 V operation with integrated LDO
Ultra Low Power Mode w/ LCD (<3 µA typical)
Shutdown current (0.05 µA typical)
Example Applications
Handheld Equipment
Utility Meters
Thermostat Display
Home Security Systems
Packages
Pb-free 48-pin QFP (9x9 mm footprint) [-Q]
Pb-free 48-pin QFN (7x7 mm footprint) [-M]
Pb-free 32-pin QFN (5x5 mm footprint)
Ordering Part Numbers
CP2400-G[M|Q] (SPI Interface)
CP2401-G[M|Q] (SMBus/I2C Interface)
CP2402-GM (SPI Interface)
CP2403-GM (SMBus/I2C Interface)
Temperature Range: –40 to +85 °C
Host
Interface
SPI
(CP2400/2)
OR
SMBus/I2C
(CP2401/3)
20 MHz
Internal
Oscillator
256 Byte
SRAM
2 x 16-bit
Timers GPIO Expander
smaRTClock 32.768 kHz
CP2400/1/2/3
Host
Controller Digital I/O
Optional
LCD Controller LCD
CP2400/1/2/3
2 Rev. 1.0
CP2400/1/2/3
Rev. 1.0 3
1. System Overview.................................................................................................................5
1.1. Typical Connection Diagram..........................................................................................9
2. Absolute Maximum Ratings..............................................................................................11
3. Electrical Characteristics..................................................................................................12
4. Pinout and Package Definitions.......................................................................................17
5. Clocking Options...............................................................................................................32
6. Internal Registers and Memory ........................................................................................34
6.1. Accessing Internal Registers and RAM over the SPI Interface....................................35
6.2. Accessing Internal Registers and RAM over the SMBus Interface..............................36
6.3. Internal Registers.........................................................................................................37
7. Interrupt Sources...............................................................................................................40
8. Reset Sources....................................................................................................................47
8.1. Reset Initialization........................................................................................................47
8.2. Power-On Reset...........................................................................................................48
8.3. External Pin Reset........................................................................................................48
9. Power Modes......................................................................................................................49
9.1. Normal Mode................................................................................................................50
9.2. RAM Preservation Mode..............................................................................................50
9.3. Ultra Low Power LCD Mode.........................................................................................51
9.4. Ultra Low Power SmaRTClock Mode...........................................................................52
9.5. Shutdown Mode ...........................................................................................................53
9.6. Determining the ULP Mode Wake-Up Source..............................................................55
9.7. Port Match Functionality in the Ultra Low Power Modes..............................................56
9.8. Disabling Secondary Device Functions........................................................................58
10.Port Input/Output...............................................................................................................60
10.1.Port I/O Modes of Operation........................................................................................61
10.2.Assigning Port I/O Pins to Analog and Digital Functions.............................................62
10.3.Active Mode Port Match...............................................................................................63
10.4.Registers for Accessing and Configuring Port I/O .......................................................65
11.SmaRTClock (Real Time Clock)........................................................................................69
11.1.SmaRTClock Interface.................................................................................................70
11.2.SmaRTClock Clocking Sources...................................................................................74
11.3.SmaRTClock Timer and Alarm Function .....................................................................77
12.LCD Segment Driver..........................................................................................................83
12.1.Initializing the LCD Segment Driver.............................................................................83
12.2.LCD Configuration . ......................................................................................................84
12.3.LCD Bias Generation and Contrast Adjustment ..........................................................85
12.4.LCD Timing Generation...............................................................................................87
12.5.Mapping ULP Memory to LCD Pins.............................................................................90
12.6.Blinking LCD Segments...............................................................................................91
13.Timers.................................................................................................................................92
13.1.Timer 0 .......................................................................................................................92
13.2.Timer 1 .......................................................................................................................96
14.Serial Peripheral Interface (SPI) .....................................................................................101
14.1.Signal Descriptions....................................................................................................101
14.2.Serial Clock Timing....................................................................................................102
CP2400/1/2/3
4 Rev. 1.0
15.SMBus Interface...............................................................................................................104
15.1.Supporting Documents ..............................................................................................104
15.2.SMBus Configuration.................................................................................................104
15.3.SMBus Operation.......................................................................................................105
Document Change List ........................................................................................................108
Contact Information .............................................................................................................110
CP2400/1/2/3
Rev. 1.0 5
1. System Overview
CP2400/1/2/3 devices are fixed function LCD drivers that can also be used for expanding GPIO, timekeeping, and
increasing available system RAM by up to 256 bytes. The device is controlled using direct and indirect internal
registers accessible through the 4-wire SPI or 2-wire SMBus interface. All digital pins on the device are 5 V
tolerant.
Figure 1.1. CP2400 Block Diagram
Port 0
Drivers
GPIO Exp and er
P0.0/LCD0
P0.1/LCD1
P0.2/LCD2
P0.3/LCD3
P0.4/LCD4
P0.5/LCD5
P0.6/LCD6
P0.7/LCD7
Port I/O Configuration
SFR
Bus
Port 1
Drivers
P1.0/LCD8
P1.1/LCD9
P1.2/LCD10
P1.3/LCD11
P1.4/LCD12
P1.5/LCD13
Port 2
Drivers
P2.0/LCD16
P2.1/LCD17
P2.2/LCD18
P2.3/LCD19
P2.4/LCD20
System Clock
Configuration
External
CMOS Clock
Low Power
20 MHz
Oscillator
P1.6/LCD14
P1.7/LCD15
P2.5/LCD21
P2.6/LCD22
P2.7/LCD23
SmaRTClock
Oscillator
XTAL1
XTAL2
Host Interface
Port 3
Drivers
P3.0/LCD24
P3.1/LCD25
P3.2/LCD26
P3.3/LCD27
P3.4/LCD28
P3.5/LCD29
P3.6/LCD30
P3.7/LCD31
Port 4
Drivers
P4.0/COM0
P4.1/COM1
P4.2/COM2
P4.3/COM3
CLK SYSCLK
2 x Timer (16-bit)
256 Byte SRAM
INT
MOSI
MISO
SCK
Power Net
VDD
Power On
Reset
Reset
RST
GND
VREG Digital
Power
Analog
Power
SPI
(4-wire)
LCD Control
Charge
Pump
Segment RAM
MUX Deco de Logic
CAP
Power
Management
NSS
CP2400/1/2/3
6 Rev. 1.0
Figure 1.2. CP2401 Block Diagram
Port 0
Drivers
GPIO Exp and er
P0.0/LCD0
P0.1/LCD1
P0.2/LCD2
P0.3/LCD3
P0.4/LCD4
P0.5/LCD5
P0.6/LCD6
P0.7/LCD7
Port I/O Configuration
SFR
Bus
Port 1
Drivers
P1.0/LCD8
P1.1/LCD9
P1.2/LCD10
P1.3/LCD11
P1.4/LCD12
P1.5/LCD13
Port 2
Drivers
P2.0/LCD16
P2.1/LCD17
P2.2/LCD18
P2.3/LCD19
P2.4/LCD20
System Clock
Configuration
External
CMOS Clock
Low Power
20 MHz
Oscillator
P1.6/LCD14
P1.7/LCD15
P2.5/LCD21
P2.6/LCD22
P2.7/LCD23
SmaRTClock
Oscillator
XTAL1
XTAL2
Host Interface
Port 3
Drivers
P3.0/LCD24
P3.1/LCD25
P3.2/LCD26
P3.3/LCD27
P3.4/LCD28
P3.5/LCD29
P3.6/LCD30
P3.7/LCD31
Port 4
Drivers
P4.0/COM0
P4.1/COM1
P4.2/COM2
P4.3/COM3
CLK SYSCLK
2 x Timer (16-bit)
256 Byte SRAM
INT
SCL
SDA
SMBA0
Power Net
VDD
Power On
Reset
Reset
RST
GND
VREG Digital
Power
Analog
Power
SMBus/I2C
(2-wire)
LCD Control
Charge
Pump
Segment RAM
MUX Deco de Logic
CAP
PWR Power
Management
CP2400/1/2/3
Rev. 1.0 7
Figure 1.3. CP2402 Block Diagram
Port 0
Drivers
GPIO Exp and er
P0.0/LCD0
P0.1/LCD1
P0.2/LCD2
P0.3/LCD3
P0.4/LCD4
P0.5/LCD5
P0.6/LCD6
P0.7/LCD7
Port I/O Configuration
SFR
Bus
Port 1
Drivers
P1.0/LCD8
P1.1/LCD9
P1.2/LCD10
P1.3/LCD11
P1.4/LCD12
P1.5/LCD13
System Clock
Configuration
External
CMOS Clock
Low Power
20 MHz
Oscillator
P1.6/LCD14
P1.7/LCD15
SmaRTClock
Oscillator
XTAL1
XTAL2
Host Interface
Port 2
Drivers
P2.0/COM0
P2.1/COM1
P2.2/COM2
P2.3/COM3
CLK SYSCLK
2 x Timer (16-bit)
256 Byte SRAM
INT
MOSI
MISO
SCK
Power Net
VDD
Power On
Reset
Reset
RST
GND
VREG Digital
Power
Analog
Power
SPI
(4-wire)
LCD Control
Charge
Pump
Segment RAM
MUX Deco de Logic
CAP
Power
Management
NSS
CP2400/1/2/3
8 Rev. 1.0
Figure 1.4. CP2403 Block Diagram
Port 0
Drivers
GPIO Exp and er
P0.0/LCD0
P0.1/LCD1
P0.2/LCD2
P0.3/LCD3
P0.4/LCD4
P0.5/LCD5
P0.6/LCD6
P0.7/LCD7
Port I/O Configuration
SFR
Bus
Port 1
Drivers
P1.0/LCD8
P1.1/LCD9
P1.2/LCD10
P1.3/LCD11
P1.4/LCD12
P1.5/LCD13
System Clock
Configuration
External
CMOS Clock
Low Power
20 MHz
Oscillator
P1.6/LCD14
P1.7/LCD15
SmaRTClock
Oscillator
XTAL1
XTAL2
Host Interface
Port 2
Drivers
P2.0/COM0
P2.1/COM1
P2.2/COM2
P2.3/COM3
CLK SYSCLK
2 x Timer (16-bit)
256 Byte SRAM
INT
SCL
SDA
SMBA1
Power Net
VDD
Power On
Reset
Reset
RST
GND
VREG Digital
Power
Analog
Power
SMBus/I2C
(2-wire)
LCD Control
Charge
Pump
Segment RAM
MUX Deco de Logic
CAP
PWR Power
Management
SMBA0
CP2400/1/2/3
Rev. 1.0 9
1.1. Typical Connection Diagram
Figure 1.5. Typical Connection Diagram (SPI Interface)
CP240x
XTAL2
XTAL1
32.768 kHz
VDD
VDD
0.1 uF
MCU
SCK SCK
MISO MISO
RST
LCD
GND GND
MOSI MOSI
LCD0
LCDn
COM1
COM3
COM4
COM2
COM0
COM2
COM3
COM1
Segment Pin 1
Segment Pin (n+1)
GPIO
CLK
GPIO
CAP
10 uF
INTGPIO
NSS NSS
Px.x
Px.y
GPIO, Analog, etc.
CP2400/1/2/3
10 Rev. 1.0
Figure 1.6. Typical Connection Diagram (SMBus/I2C Interface)
CP240x
XTAL2
XTAL1
32.768 kHz
VDD
VDD
0.1 uF
MCU
SCL SCL
SDA SDA
RST
LCD
GND GND
LCD0
LCDn
COM1
COM3
COM4
COM2
COM0
COM2
COM3
COM1
Segment Pin 1
Segment Pin (n+1)
GPIO
CLK
GPIO
CAP
10 uF
INTGPIO
GPIO PWR Px.x
Px.y
GPIO, Analog, etc.
SMBA0
VDD
CP2400/1/2/3
Rev. 1.0 11
2. Absolute Maximum Ratings
Table 2.1. Absolute Maximum Ratings
Parameter Conditions Min Typ Max Units
Ambient temperature under bias –55 — 125 °C
Storage Temperature –65 — 150 °C
Voltage on any I/O Pin or RST with respect to GND VDD > 2.2 V
VDD < 2.2 V –0.3 — 5.8
VDD + 3.6 V
Voltage on VDD with respect to GND –0.3 — 4.2 V
Maximum Total current through VDD and GND — — 500 mA
Maximum output current sunk by RST or any I/O pin — — 100 mA
Note: Stresses above those listed may cause permanent damage to the device. This is a stress rating only, and functional
operation of the devices at or exceeding the conditions in the opera tion listings of this specification is not implied.
Exposure to maximum rating conditions for extended periods may affect device reliability.
CP2400/1/2/3
12 Rev. 1.0
3. Electrical Characteristics
Table 3.1. Global Electrical Characteristics
VDD = 1.8 to 3.6 V, –40 to +85 °C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Supply Voltage 1.8 3.3 3.6 V
SYSCLK 0 — 25 MHz
TSYSH (SYSCLK High Time) 18 — — ns
TSYSL (SYSCLK Low Time) 18 — — ns
Specified Operating Temperature Range –40 — +85 °C
Normal Mode Supply Current (VDD = 3.0 V, 25 °C unless otherwise specified)
20 MHz Internal Oscillator divided by 1,
SYSCLK = 20 MHz, SPI data rate = 1 Mbps*VDD =3.6V
VDD =3.0V
VDD =1.8V
—
—
—
740
700
630
790
—
—
µA
Accessing RAM at 1 Mbps — 740 — µA
SYSCLK = 10 MHz, SPI data rate* = 500 kbps — 380 — µA
SYSCLK = 5 MHz, SPI data rate* = 250 kbps — 230 — µA
SYSCLK = 2.5 MHz, SPI data rate* = 125 kbps — 150 — µA
RAM Preservation Mode Supply Current (VDD = 3.0 V, 25 °C unless otherwise specified)
32.768 kHz SmaRTClock Selected as the
System Clock, Internal Oscillator Disabled —20—µA
Ultra Low Power LCD Mode Supply Current (VDD = 3.0 V, 25 °C unless otherwise specified)
LCD Enabled with Charge Pump Enabled,
60 Hz Refresh Rate, No Load
SmaRTClock with 32.768 kHz crystal
4-Mux mode
3-Mux mode
2-Mux mode
static mode
—
—
—
—
2.3
2.3
2.2
2.1
—
—
—
—
µA
LCD Enabled with Charge Pump Enabled,
60 Hz Refresh Rate, No Load
SmaRTClock in Self-Oscillate Mode (AGC
Enabled, LOADCAP = 0x0F)
4-Mux mode
3-Mux mode
2-Mux mode
static mode
—
—
—
—
1.7
1.7
1.7
1.5
—
—
—
—
µA
Ultra Low Power SmaRTClock Mode Supply Current (VDD = 3.0 V, 25 °C unless otherwise specified)
External Crystal (RTC Timer Enabled) Fosc = 32.768 kHz — 2.5 — µA
CMOS Clock Input on XTAL1 and XTAL2 Pins
(RTC Timer Enabled) Fosc = 32.768 kHz — 2.3 — µA
Self-Oscillate Mode (AGC enabled,
LOADCAP = 0x0F) (RTC Timer Enabled) Fosc = 14 kHz — 2.0 — µA
Shutdown Mode (VDD = 3.0 V, 25 °C unless otherwise specified)
Shutdown (no clocks active, regulator disabled) VDD =3.6V
VDD =3.0V
VDD =1.8V
—
—
—
0.030
0.020
0.015
—
—
—
µA
*Note: Indicates maximum allowed SPI data rate in this mode. Power measurement taken with no SPI traffic.
CP2400/1/2/3
Rev. 1.0 13
Table 3.2. Port I/O DC Electrical Characteristics
VDD = 1.8 to 3.6 V, –40 to +85 °C unless otherwise specified.
Parameters Conditions Min Typ Max Units
Output High Voltage High Drive Strength, PnDRV.n = 1
IOH = –3 mA, Port I/O push-pull
IOH = –10 µA, Port I/O push-pull
IOH = –10 mA, Port I/O push-pull
Low Drive Strength, PnDRV.n = 0
IOH = –1 mA, Port I/O push-pull
IOH = –10 µA, Port I/O push-pull
IOH = –3 mA, Port I/O push-pull
VDD –0.7
VDD –0.1
—
VDD –0.7
VDD –0.1
—
—
—
See Chart
—
—
See Chart
—
—
—
—
—
—
V
Output Low Voltage High Drive Strength, PnDRV.n = 1
IOL = 8.5 mA
IOL = 10 µA
IOL = 15 mA
Low Drive Strength, PnDRV.n = 0
IOL = 1.4 mA
IOL = 10 µA
IOL = 4 mA
—
—
—
—
—
—
—
—
See Chart
—
—
See Chart
0.6
0.1
—
0.6
0.1
—
V
Input High Voltage VDD = 2.0 to 3.6 V VDD – 0.6 ——V
VDD = 1.8 to 2.0 V 0.7 x VDD ——V
Input Low Voltage VDD = 2.0 to 3.6 V — — 0.6 V
VDD = 1.8 to 2.0 V ——
0.3 x VDD V
Input Leakage
Current Weak Pullu p On, VIN = 0 V, VDD = 1.8 V
Weak Pullup On, Vin = 0 V, VDD = 3.6 V —
—4
20 —
30 µA
CP2400/1/2/3
14 Rev. 1.0
Figure 3.1. Typical VOH
Typical VOH (High Drive Mode)
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3
3.3
3.6
0 5 10 15 20 25 30 35 40 45 50
Load Cur ren t ( m A)
Voltag
e
VDD = 3.6V
VDD = 3.0V
VDD = 2.4V
VDD = 1.8V
Typical VOH (Low Drive Mo de)
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3
3.3
3.6
0123456789101112131415
Load Current (m A)
Voltag
e
V DD = 3.6V
V DD = 3.0V
V DD = 2.4V
V DD = 1.8V
CP2400/1/2/3
Rev. 1.0 15
Figure 3.2. Typical VOL
Typical VO L (H igh Dr ive Mode)
0
0.3
0.6
0.9
1.2
1.5
1.8
-80 -70 -60 -50 -40 -30 -20 -10 0 10
Load Cur rent (mA)
Voltag
e
VDD = 3.6 V
VDD = 3.0 V
VDD = 2.4 V
VDD = 1.8 V
Typical VOL (Low Drive Mode)
0
0.3
0.6
0.9
1.2
1.5
1.8
-10-9-8-7-6-5-4-3-2-10
Load Cur rent (mA)
Voltag
e
VDD = 3 .6V
VDD = 3 .0V
VDD = 2 .4V
VDD = 1 .8V
CP2400/1/2/3
16 Rev. 1.0
Table 3.3. Reset Electrical Characteristics
VDD = 1. 8 to 3.6 V, –40 to +8 5 °C unless otherwise specified.
Parameters Conditions Min Typ Max UNITS
RST Input High Voltage 0.7 x VDD ——V
RST Input Low Voltage — — 0.3 x VDD V
RST Input Pullup Current RST = 0 V, VDD = 1.8 V
RST = 0 V, VDD = 3.6 V —
—4
20 —
30 µA
VDD Ramp Time for Power On1VDD Ramp from 0–1.8 V —— 1ms
Power on Reset Delay (TPORDelay)
from Start of Ramp until the Reset
Complete Interrupt
VDD = 1.8 V
VDD = 3.0 V
VDD = 3.6 V
—
—
—
1200
660
575
—
900
—
µs
Required RST Low Time to
guarantee a System Reset (TRST)See Note 2 15 — — µs
Startup Delay from Reset De-
asserted until the Reset Complete
Interrupt (TSTARTUP)
Pin Reset — 90 100 µs
Notes:
1. There is no restriction on VDD ramp time if the RST pin is toggled at the end of the ramp.
2. If the RST pin is held low for a shorter time period, a device reset may occur.
Table 3.4. Power Management Electrical Specifications
VDD = 1.8 to 3.6 V, –40 to +85 °C unless otherwise specified.
Parameter Conditions Min Typ Max Units
RAM Preservation Mode W ake-Up
Time From the falling edge of CLK until
host interface ready 10 ns
ULP Mode Wake-Up Time (from
the falling edge of NSS/PWR to
the reset complete interrupt)
Port Match or SmaRTClock W akeup
NSS/PWR Pin Wakeup
3
7—
—4
8RTC
Cycles
Table 3.5. Internal Oscillator Electrical Characteristics
VDD = 1.8 to 3.6 V ; TA = –40 to +85 °C unless otherwise specified; Using factory-calibrated settings.
Parameter Conditions Min Typ Max Units
Oscillator Frequency –40 to +85 °C,
VDD = 1.8–3.6 V 15 20 25 MHz
Oscillator Supply Current (from VDD)25 °C — 50 — µA
Table 3.6. LCD Electrical Characteristics
VDD = 1.8 to 3.6 V ; TA = –40 to +85 °C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Charge Pump Output Voltage Error — ±30 — mV
CP2400/1/2/3
Rev. 1.0 17
4. Pinout and Package Definitions
Table 1. CP2400/1/2/3 Pin Definitions
Name Pin Numbers Type Description
48-pin 32-pin
SPI I2CSPI I2C
XTAL1 1 1 1 1 A In Crystal Input. This pin is the return for the external oscillator
driver. This pin can be overdriven by an external CMOS clock.
XTAL2 2 2 2 2 A Out Crystal Output. This pin is the excitation driver for a quartz
crystal.
VDD 3 3 3 3 Power In 1.8–3.6 V Power Supply Voltage Input.
GND 4 4 4 4 Ground
CAP 48483232Power
Out LCD Power Supply Voltage Output. This pin requ ires a 10 µF
decoupling capacitor.
CLK 47 47 31 31 D In CMOS clock input. This pin should not be left floating.
RST 46 46 30 30 D In Device Rese t. An ex tern al source can initiate a system reset by
driving this pin low for at least 15 µs. This pin has an internal
weak pullup.
INT 45 45 29 29 D Out Interrupt Service Request. This pin provides notification to the
host. This pin is a push-pull output.
NSS 44 — 28 — D In Slave select signal for SPI interface. This pin should not be left
floating.
MOSI 43 — 27 — D In Master Out/Slave In data signal for SPI interface. This pin
should not be left floating.
MISO 42 — 26 — D Out Master In/Slave Out data signal for SPI interface
SCK 41 — 25 — D In Clock signal for SPI interface. This pin should not be left
floating.
PWR — 44 — 28 D In Allows SMBus device to enter the Ultra Low Power mode. This
pin should not be left floating.
SCL — 43 — 27 D I/O Clock signal for SMBus interface. This pin should not be lef t
floating.
SDA — 42 — 26 D I/O Data signal for SMBus interface. This pin should not be left
floating.
SMBA0 — 41 — 25 D In Bit 0, SMBus Slave Address. This pin should not be left floating.
P0.0
LCD0 40 40 24 24 D I/O
A Out Bit 0, Port 0
P0.1
LCD1 39 39 23 23 D I/O
A Out Bit 1, Port 0
CP2400/1/2/3
18 Rev. 1.0
P0.2
LCD2 38 38 22 22 D I/O
A Out Bit 2, Port 0
P0.3
LCD3 37 37 21 21 D I/O
A Out Bit 3, Port 0
P0.4
LCD4 36 36 20 20 D I/O
A Out Bit 4, Port 0
P0.5
LCD5 35 35 19 19 D I/O
A Out Bit 5, Port 0
P0.6
LCD6 34 34 18 18 D I/O
A Out Bit 6, Port 0
P0.7
LCD7 33 33 17 17 D I/O
A Out Bit 7, Port 0
P1.0
LCD8 32 32 16 16 D I/O
A Out Bit 0, Port 1
P1.1
LCD9 31 31 15 15 D I/O
A Out Bit 1, Port 1
P1.2
LCD10 30 30 14 14 D I/O
A Out Bit 2, Port 1
P1.3
LCD11 29 29 13 13 D I/O
A Out Bit 3, Port 1
P1.4
LCD12 28 28 12 12 D I/O
A Out Bit 4, Port 1
P1.5
LCD13 27 27 11 11 D I/O
A Out Bit 5, Port 1
P1.6
LCD14 26 26 10 10 D I/O
A Out Bit 6, Port 1
P1.7
LCD15 25 25 9 9 D I/O
A Out Bit 7, Port 1
P2.0
LCD16 24 24 — — D I/O
A Out Bit 0, Port 2
P2.1
LCD17 23 23 — — D I/O
A Out Bit 1, Port 2
Table 1. CP2400/1/2/3 Pin Definitions (Continued)
Name Pin Numbers Type Description
48-pin 32-pin
SPI I2CSPI I2C
CP2400/1/2/3
Rev. 1.0 19
P2.2
LCD18 22 22 — — D I/O
A Out Bit 2, Port 2
P2.3
LCD19 21 21 — — D I/O
A Out Bit 3, Port 2
P2.0
COM0 — — 8 8 D I/O
A Out Bit 0, Port 2
P2.1
COM1 — — 7 7 D I/O
A Out Bit 1, Port 2
P2.2
COM2 — — 6 6 D I/O
A Out Bit 2, Port 2
P2.3
COM3 — — 5 5 D I/O
A Out Bit 3, Port 2
P2.4
LCD20 20 20 — — D I/O
A Out Bit 4, Port 2
P2.5
LCD21 19 19 — — D I/O
A Out Bit 5, Port 2
P2.6
LCD22 18 18 — — D I/O
A Out Bit 6, Port 2
P2.7
LCD23 17 17 — — D I/O
A Out Bit 7, Port 2
P3.0
LCD24 16 16 — — D I/O
A Out Bit 0, Port 3
P3.1
LCD25 15 15 — — D I/O
A Out Bit 1, Port 3
P3.2
LCD26 14 14 — — D I/O
A Out Bit 2, Port 3
P3.3
LCD27 13 13 — — D I/O
A Out Bit 3, Port 3
P3.4
LCD28 12 12 — — D I/O
A Out Bit 4, Port 3
P3.5
LCD29 11 11 — — D I/O
A Out Bit 5, Port 3
Table 1. CP2400/1/2/3 Pin Definitions (Continued)
Name Pin Numbers Type Description
48-pin 32-pin
SPI I2CSPI I2C
CP2400/1/2/3
20 Rev. 1.0
P3.6
LCD30 10 10 — — D I/O
A Out Bit 6, Port 3
P3.7
LCD31 9 9 — — D I/O
A Out Bit 7, Port 3
P4.0
COM0 8 8 — — D I/O
A Out Bit 0, Port 4
P4.1
COM1 7 7 — — D I/O
A Out Bit 1, Port 4
P4.2
COM2 6 6 — — D I/O
A Out Bit 2, Port 4
P4.3
COM3 5 5 — — D I/O
A Out Bit 3, Port 4
Table 1. CP2400/1/2/3 Pin Definitions (Continued)
Name Pin Numbers Type Description
48-pin 32-pin
SPI I2CSPI I2C
CP2400/1/2/3
Rev. 1.0 21
Figure 4.1. CP2400-GQ Pinout (SPI Interface)
Figure 4.2. CP2401-GQ Pinout (SMBus/I2C Interface)
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
48
47
46
45
44
43
42
41
40
39
38
37
P3.4/LCD28
P0.4/LCD4
P0.2/LCD2
P0.1/LCD1
P0.0/LCD0
NSS
P0.6/LCD6
P0.5/LCD5
P1.7/LCD15
P1.6/LCD14
P1.4/LCD12
P1.3/LCD11
P0.3/LCD3
CAP
P1.5/LCD13
CLK
GND
P3.7/LCD31
P3.5/LCD29
VDD
P1.2/LCD10
MISO
SCK
XTAL1
INT
RST
XTAL2
MOSI
13
14
15
16
17
18
19
20
21
22
23
24
P1.0/LCD8
P0.7/LCD7
CP2400 - GQ
Top View
P4.1/COM1
P4.0/COM0
P4.3/COM3
P4.2/COM2
P3.6/LCD30
P1.1/LCD9
P2.0/LCD16
P2.3/LCD19
P2.2/LCD18
P2.1/LCD17
P2.4/LCD20
P2.7/LCD23
P2.6/LCD22
P2.5/LCD21
P3.0/LCD24
P3.3/LCD27
P3.2/LCD26
P3.1/LCD25
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
48
47
46
45
44
43
42
41
40
39
38
37
P3.4/LCD28
P0.4/LCD4
P0.2/LCD2
P0.1/LCD1
P0.0/LCD0
PWR
P0.6/LCD6
P0.5/LCD5
P1.7/LCD15
P1.6/LCD14
P1.4/LCD12
P1.3/LCD11
P0.3/LCD3
CAP
P1.5/LCD13
CLK
GND
P3.7/LCD31
P3.5/LCD29
VDD
P1.2/LCD10
SDA
SMBAD0
XTAL1
INT
RST
XTAL2
SCL
13
14
15
16
17
18
19
20
21
22
23
24
P1.0/LCD8
P0.7/LCD7
CP2401 - GQ
Top View
P4.1/COM1
P4.0/COM0
P4.3/COM3
P4.2/COM2
P3.6/LCD30
P1.1/LCD9
P2.0/LCD16
P2.3/LCD19
P2.2/LCD18
P2.1/LCD17
P2.4/LCD20
P2.7/LCD23
P2.6/LCD22
P2.5/LCD21
P3.0/LCD24
P3.3/LCD27
P3.2/LCD26
P3.1/LCD25
CP2400/1/2/3
22 Rev. 1.0
Figure 4.3. CP2400-GM Pinout (SPI Interface)
Figure 4.4. CP2401-GM Pinout (SMBus/I2C Interface)
P1.2/LCD10
P1.1/LCD9
P1.0/LCD8
P0.7/LCD7
P0.6/LCD6
P0.5/LCD5
33
34
35
31
30
32
P0.4/LCD436
P1.3/LCD1129
P1.6/LCD14
P1.5/LCD13
P1.4/LCD12
27
26
28
P1.7/LCD1525
GND
XTAL2
VDD
P4.3/COM3
P4.2/COM2
P4.1/COM1
5
6
7
4
3
2
P4.0/COM0 8
XTAL1 1
P3.7/LCD31
P3.6/LCD30
P3.5/LCD29
9
10
11
P3.4/LCD28 12
GND
MISO
MOSI
NSS
INT
RST
CAP
45
46
47
43
42
44
CLK
48
SCK41
P0.2/LCD2
P0.1/LCD1
P0.0/LCD0
39
38
40
P0.3/LCD337
P3.2/LCD26
P3.1/LCD25
P3.0/LCD24
P2.7/LCD23
P2.6/LCD22
P2.5/LCD21
17
18
19
15
14
16
P2.4/LCD20 20
P3.3/LCD27 13
P2.3/LCD19
P2.2/LCD18
P2.1/LCD17
21
22
23
P2.0/LCD16 24
CP 2400 - G M
Top View
P1.2/LCD10
P1.1/LCD9
P1.0/LCD8
P0.7/LCD7
P0.6/LCD6
P0.5/LCD5
33
34
35
31
30
32
P0.4/LCD436
P1.3/LCD1129
P1.6/LCD14
P1.5/LCD13
P1.4/LCD12
27
26
28
P1.7/LCD1525
GND
XTAL2
VDD
P4.3/COM3
P4.2/COM2
P4.1/COM1
5
6
7
4
3
2
P4.0/COM0 8
XTAL1 1
P3.7/LCD31
P3.6/LCD30
P3.5/LCD29
9
10
11
P3.4/LCD28 12
GND
SMBA0
SDA
SCL
INT
RST
PWR
45
46
47
43
42
44
CLK
48 CAP
41
P0.2/LCD2
P0.1/LCD1
P0.0/LCD0
39
38
40
P0.3/LCD337
P3.2/LCD26
P3.1/LCD25
P3.0/LCD24
P2.7/LCD23
P2.6/LCD22
P2.5/LCD21
17
18
19
15
14
16
P2.4/LCD20 20
P3.3/LCD27 13
P2.3/LCD19
P2.2/LCD18
P2.1/LCD17
21
22
23
P2.0/LCD16 24
C P2401 - GM
Top View
CP2400/1/2/3
Rev. 1.0 23
Figure 4.5. CP2402-GM Pinout (SPI Interface)
Figure 4.6. CP2403-GM Pinout (SMBus Interface)
21
22
23
19
18
20
24
17
GND
5
6
7
4
3
2
8
1
29
30
31
27
26
28
32
25
C P2402 - GM
Top View
13
14
15
11
10
12
16
9
P0.6/LCD6
P0.5/LCD5
P0.4/LCD4
P0.3/LCD3
P0.2/LCD2
P0.1/LCD1
P0.0/LCD0
P0.7/LCD7
MISO
MOSI
NSS
INT
RST
CAP
SCK
CLK
XTAL2
VDD
P2.3/COM3
P2.2/COM2
P2.1/COM1
P2.0/COM0
XTAL1
GND
P1.6/LCD14
P1.5/LCD13
P1.4/LCD12
P1.3/LCD11
P1.2/LCD10
P1.1/LCD9
P1.0/LCD8
P1.7/LCD15
P0.6/LCD6
P0.5/LCD5
P0.4/LCD4
P0.3/LCD3
P0.2/LCD2
P0.1/LCD1
21
22
23
19
18
20
P0.0/LCD0
24
P0.7/LCD7
17
GND
XTAL2
VDD
P2.3/COM3
P2.2/COM2
P2.1/COM1
5
6
7
4
3
2
P2.0/COM0 8
XTAL1 1
GND
SMBA0
SDA
SCL
INT
RST
PWR
29
30
31
27
26
28
CLK
32 CAP
25
CP2403 - GM
Top View
P1.6/LCD14
P1.5/LCD13
P1.4/LCD12
P1.3/LCD11
P1.2/LCD10
P1.1/LCD9
13
14
15
11
10
12
P1.0/LCD8 16
P1.7/LCD15 9
CP2400/1/2/3
24 Rev. 1.0
Figure 4.7. QFN-48 Package Drawing
Notes:
1. All dimensions shown are in millimeters (mm)
unless otherw ise no te d .
2. Dimensioning and Tolerancing per ANSI
Y14.5M-1994.
3. This drawing confor ms to JEDEC outline
MO-220, variation VKKD-4 except for
features D2 and L which are toleranced per
supplier designation.
4. Recommended card reflow profile is per the
JEDEC/IPC J-STD-020 specification for
Small Body Components.
CP2400/1/2/3
Rev. 1.0 25
Figure 4.8. QFN-48 Landing Diagram
CP2400/1/2/3
26 Rev. 1.0
Table 4.1. PCB Land Pattern
Dimension MIN MAX
C1 6.80 6.90
C2 6.80 6.90
e 0.50 BSC
X1 0.20 0.30
X2 4.00 4.10
Y1 0.75 0.85
Y2 4.00 4.10
Notes:
General
3. All dimensions shown are in millimeters (mm) unless otherwise noted.
4. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.
5. This Land Pattern Design is based on IPC-SM-782 guidelines.
6. All dimensions shown are at Maximum Ma terial Condition (MMC). Least Material
Condition (LMC) is calculated based on a Fabrication Allowance of 0.05 mm.
Solder Mask Design
1. All metal pads are to be non-solder mask defined (NSMD). Clearance between the
solder mask and the metal pad is to be 60 µm minimum, all the way around the pad.
Stencil Design
1. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should
be used to assure good solder paste release.
2. The stencil thickness should be 0.125 mm (5 mils).
3. The ratio of stencil aperture to land pad size should be 1:1 for all perime ter pads.
4. A 3 x 3 arra y of 1.20 mm square openings on 1.40 mm pitch should be used for the
center ground pad.
Card Assembly
1. A No-Clean, Type-3 solder paste is recommended.
2. The recommended card reflow profi l e is per the JEDEC/IPC J-STD-020 specification
for Small Body Components.
CP2400/1/2/3
Rev. 1.0 27
Figure 4.9. TQFP-48 Package Diagram
Table 4.2. TQFP-48 Package Dimensions
Dimension Min Nom Max
A——1.20
A1 0.05 — 0.15
A2 0.95 1.00 1.05
b 0.17 0.22 0.27
c0.09—0.20
D9.00 BSC
D1 7.00 BSC
e0.50 BSC
E9.00 BSC
E1 7.00 BSC
L 0.45 0.60 0.75
aaa 0.20
bbb 0.20
ccc 0.08
ddd 0.08
0° 3.5° 7°
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to JEDEC outline MS-026, variation ABC.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020C
specification for Small Body Components.
CP2400/1/2/3
28 Rev. 1.0
Figure 4.10. TQFP-48 Recommended PCB Land Pattern
Table 4.3. TQFP-48 PCB Land Pattern Dimensions
Dimension Min Max
C1 8.30 8.40
C2 8.30 8.40
E 0.50 BSC
X1 0.20 0.30
Y1 1.40 1.50
Notes:
General:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This Land Pattern Design is based on the IPC-7351 gu idelines.
Solder Mask Design:
3. All metal pads are to be non-solder mask defined (NSMD). Clearance between
the solder mask and the metal pad is to be 60 µm minimum, all the way around
the pad.
Stencil Design:
4. A stainless steel, laser-cut and el ectro-polished stencil with trapezoidal walls
should be used to assu re good solder paste release.
5. The stencil t hickness should be 0.125 mm (5 mils).
6. The ratio of stencil aperture to land pad size should be 1:1 for all pads.
Card Assembly:
7. A No-Clean, Type-3 solder paste is recommended.
8. The recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
CP2400/1/2/3
Rev. 1.0 29
Figure 4.11. QFN-32 Package Drawing
Table 4.4. QFN-32 Package Dimensions
Dimension Min Typ Max Dimension Min Typ Max
A 0.80 0.9 1.00 E2 3.20 3.30 3.40
A1 0.00 0.02 0.05 L 0.30 0.40 0.50
b 0.18 0.25 0.30 L1 0.00 — 0.15
D 5.00 BSC aaa — — 0.15
D2 3.20 3.30 3.40 bbb — — 0.10
e 0.50 BSC ddd — — 0.05
E 5.00 BSC eee — — 0.08
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MO-220, variatio n VHHD except
for custom features D2, E2, and L which are toleranced per supplier designation.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small
Body Components.
CP2400/1/2/3
30 Rev. 1.0
Figure 4.12. Typical QFN-32 Landing Diagram
CP2400/1/2/3
Rev. 1.0 31
Table 4.5. PCB Land Pattern
Dimension MIN MAX
C1 4.80 4.90
C2 4.80 4.90
E 0.50 BSC
X1 0.20 0.30
X2 3.20 3.40
Y1 0.75 0.85
Y2 3.20 3.40
Notes:
General
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.
3. This Land Pattern Design is based on the IPC-7351 guidelines.
4. All dimensions shown are at Maximum Ma terial Condition (MMC). Least Material
Condition (LMC) is calculated based on a Fabrication Allowance of 0.05 mm.
Solder Mask Design
1. All metal pads are to be non-solder mask defined (NSMD). Clearance between the
solder mask and the metal pad is to be 60 µm minimum, all the way around the pad.
Stencil Design
1. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should
be used to assure good solder paste release.
2. The stencil thickness should be 0.125 mm (5 mils).
3. The ratio of stencil aperture to land pad size should be 1:1 for all perime ter pads.
4. A 3 x 3 array of 1.0 mm square openings on 1.25 mm pitch should be used for the
center ground pad.
Card Assembly
1. A No-Clean, Type-3 solder paste is recommended.
2. The recommended card reflow profi l e is per the JEDEC/IPC J-STD-020 specification
for Small Body Components.
CP2400/1/2/3
32 Rev. 1.0
5. Clocking Options
CP2400/1/2/3 devices include a 20 MHz internal oscillator that is selected as the system clock source upon reset.
Additional clocking options include an external CMOS clock input, the internal oscillator divided by 2, 4, or 8, and
the SmaRTClock real time clock oscillator. The system clock source is selected using the CLKSEL register. The
system clock selection may always be overridden by an external CMOS clock if the CLKOVR bit (MSCN.2) is set.
Figure 5.1. Clocking Options
Internal Register Address = 0x32
SFR Definition 5.1. CLKSL: Clock Select
Bit76543210
Name CLKSL
Type R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:3 Unused Read = 00000. Write = Don’t Care.
2:0 CLKSL System Clock Sel ec t.
Selects the oscillator to be used as system clock source.
000: Internal oscillator divided by 1.
001: Internal oscillator divided by 2.
010: Internal oscillator divided by 4.
011: Internal oscillator divided by 8.
100: CMOS clock (CLK pin).
101: SmaRTClock oscillator.
All other values reserved.
Sm aR TClock
Oscillator
XTAL1
XTAL2
20 MH z Internal
Oscillator
SYSCLK
CLKSEL
CLKSL5
CLKSL4
CLKSL3
CLKSL2
CLKSL1
CLKSL0
2
4
8
CLK
CMOS
Clock
32.768 kHz CMOS
Clock
MSCN
CLKOVR
CP2400/1/2/3
Rev. 1.0 33
Internal Register Address = 0x33
Internal Register Address = 0x34
SFR Definition 5.2. IOSCCN: Internal Oscillator Control
Bit76543210
Name Reserved INTCTL OSCEN EXTCTL
Type R/W R/W R/W R/W R/W R/W
Reset 00000110
Bit Name Function
7:4 Unused Read = 00000. Write = Don’t Care.
3 Reserved Read = 0. Write = Must Write 0b.
2 INTCTL Oscillator Internal Control Enable.
When set to 1, forces the oscillator to remain enabled. Setting this bit to 0 will gate the clock
output, but will not disable the oscillator.
1 OSCEN Internal Oscillator Enable.
When set to 0, disables power to the internal oscillator. When set to 1, allows the internal
oscillator to be powered (under the control of INTCTL and EXTCTL).
0EXTCTL
Oscillator External Control Enable.
When set to 1 and INTCTL is cleared to 0, a rising edge on CLK will cause the internal
oscillator to be disabled. The internal oscillator is re-enabled by the next falling edge on CLK.
Note: To control t he intern al oscillat or enable f rom an exte rnal pi n (EXTCTL = 1, INTCTL = 0), first write both bits to logic 1,
then clear the INTCTL bit. See Section “9.2. RAM Preservation Mode” on page 50 for information on how to
place the device in RAM Preservation Mode. When running from an external clock, the internal oscillator may be dis-
abled by writing 0x00 to IOSCCN.
SFR Definition 5.3. REVID: Revision Identification
Bit76543210
Name REVID[7:0]
Type R/W
Reset Varies Varies Varies Varies Varies Varies Varies Varies
Bit Name Function
7:0 REVID[7:0] Revision ID.
Indicates the device revision. For example 0x01 indicates Revision C.
CP2400/1/2/3
34 Rev. 1.0
6. Internal Registers and Memory
The CP2400/1/2/3 is controlled by internal registers and provides the system with up to 256 bytes of additional
RAM. The internal registers and memory are controlled through an indirect interface accessible through a 4-wire
SPI interface (CP2 400/2) or 2-wire SMBus/I 2C interface (CP2401/3). A memory map of the internal registers and
RAM is shown in Figure 6.1. The internal registers are listed in “6.3. Internal Registers” on page 37.
Figure 6.1. Internal Register and RAM Memory Map
Static RAM (256 Bytes)
0x0400 – 0x04FF
Internal Registers
0x0000 – 0x00FF
ADDRH:ADDRL
Reserved
0x0100 – 0x03FF
CP2400/1/2/3
Rev. 1.0 35
6.1. Accessing Internal Registers and RAM over the SPI Interface
The SPI interface supports 6 commands which provide access to all internal registers and RAM. The six
commands are listed in Table 6.1. Detailed information on the SPI interface including bus timing can be found in
Section “14. Serial Peripheral Interface (SPI)” on page 101.
Figure 6.2 shows a typical SPI transfer used to access internal registers or RAM. The first three bytes of the
transfer are interpreted as COMMAND, ADDRH, and ADDRL. On a re ad, the fourth byte is a wait st ate in which the
SPI shift register conten t s ar e ignored ; starting with the fif th byte, da t a transfer begins. On a write, the fourth byte is
the first data byte. The direction of data transfer depends on the specified command. The SPI transaction ends
when NSS is de-asserted.
Figure 6.2. SPI Transfer
Note: Using the RAMREAD command to read an address outside the 0x4 00–0x4FF range will result in a data value of 0xDE.
Table 6.1. SPI Command Set
Command OPCODE Description
REGPOLL 0x01 Reads data from a single register. Used for polling a status bit.
REGREAD 0x02 Reads one or more bytes from registers with sequential addresses.
REGSET 0x03 Writes one or mo re byte s to a sing le regi ste r. Used for gener atin g a
waveform on a GPIO pin or updating the SmaRTClock registers.
REGWRITE 0x04 Writes one or more bytes to registers with sequential addresses.
RAMREAD 0x06 Reads one or more bytes from sequential RAM locations.
RAMWRITE 0x08 Writes one or more bytes to sequential RAM locations.
COMMAND ADDRH ADDRL WAIT DATA 0 DATA N
Read:
COMMAND ADDRH ADDRL DATA 0 DATA 1 DATA N
Write:
CP2400/1/2/3
36 Rev. 1.0
6.2. Accessing Internal Registers and RAM over the SMBus Interface
The SMBus interface supports 6 commands which provide access to all internal registers and RAM. The six
commands are listed in Table 6.2. Det ailed information on th e SMBus interface incl uding bus timing can be found in
Section “15. SMBus Interface” on page 104.
Figure 6.3 shows typical SMBus read and write transfers used to access internal registers or RAM. The first three
bytes of a write transfer are interpreted as COMMAND, ADDRH, and ADDRL. For the REGPOLL, REGREAD, and
RAMREAD commands, a repeated start is required to begin data transfer. The host controller may also choose to
end the transfer with a STOP and then start a new read transfer using the same setup information. For the WRITE
and RAMWRITE command, an SMBus write transfer is required. Starting with the fourth byte following the slave
address, all bytes written are interpreted as data. The SMBus transfer ends when the host sends a STOP.
Figure 6.3. SMBus Transfers
Note: Using the RAMREAD command to read an address outside the 0x4 00–0x4FF range will result in a data value of 0xDE.
Table 6.2. SMBus Command Set
Command OPCODE Description
REGPOLL 0x01 Reads data from a single register. Used for polling a status bit.
REGREAD 0x02 Reads one or more bytes from registers with sequential addresses.
REGSET 0x03 Writes one or mo re byte s to a sing le regi ste r. Used for gener atin g a
waveform on a GPIO pin or updating the SmaRTClock registers.
REGWRITE 0x04 Writes one or more bytes to registers with sequential addresses.
RAMREAD 0x06 Reads one or more bytes from sequential RAM locations.
RAMWRITE 0x08 Writes one or more bytes to sequential RAM locations.
PWSLASCOMMAND A
R = READ
W = WRITE
SLA = Slave Address
Received by
CP240x
Transmitted by
CP240x
ADDRH AADDRL AA Data 0 AData N A
SMBus Write:
P
WSLASCOMMAND AADDRH AADDRL AA
AData 0
SMBus Read (Setup):
RSLA
S
RA NData N
S = START
R = REPEATED START
P = STOP
A = ACK
N = NACK
SMBus Read (Data Transfer):
+ Data Transfer or STOP
CP2400/1/2/3
Rev. 1.0 37
6.3. Internal Registers
The CP2400/1/2/3 interna l registers are grouped into categories based on function. The memory map is organized
to minimize register access time, by sequentially locating registers that can be read or written with a single block
read or write. Table 6.3 shows the register memory map for all registers available on the device.
Table 6.3. Internal Register Memory Map
Register Address Description Preserved Page No.
SmaRTClock Registers
RTCKEY 0x0A RTC0 Indirect Address N 72
RTCADR 0x0B RTC0 Indirect Data N 73
RTCDAT 0x0C RTC0 Lock and Key N 73
Interrupt Mask and Clocking Registers
INT0EN 0x30 Interrupt Enable Register 0 N 43
INT1EN 0x31 Interrupt Enable Register 1 N 46
CLKSL 0x32 Clock Select N 32
IOSCCN 0x33 Internal Oscillator Control N 33
REVID 0x34 Revision Identifier Y 33
Interrupt Status Registers
INT0RD 0x40 Interrupt Status Register 0 (read-only) N 42
INT1RD 0x41 Interrupt Status Register 1 (read-only) N 45
ULPST 0x42 Ultra Low Power Status Y 55
INT0 0x43 Interrupt Status Register 0 (self-clearing) N 41
INT1 0x44 Interrupt Status Register 1 (self-clearing) N 44
Timer 0 and Timer 1 Registers
TMR0RLL 0x50 Timer 0 Reload Register Low Byte N 94
TMR0RLH 0x51 Timer 0 Reload Register High Byte N 94
TMR0L 0x52 Timer 0 Low Byte N 95
TMR0H 0x53 Timer 0 High Byte N 95
TMR0CN 0x54 Timer 0 Control N 93
TMR1RLL 0x55 Timer 1 Reload Register Low Byte N 99
TMR1RLH 0x56 Timer 1 Reload Register High Byte N 99
TMR1L 0x57 Timer 1 Low Byte N 100
TMR1H 0x58 Timer 1 High Byte N 100
TMR1CN 0x59 Timer 1 Control N 98
SMBus Registers
SMBCF 0x68 SMBus Configuration N 107
ULP/LCD0 Data Registers
LCD0BLINK 0x80 LCD0 Segment Blink Y 91
ULPMEM00 0x81 ULP Memory Byte 0 Y 57
ULPMEM01 0x82 ULP Memory Byte 1 Y 57
ULPMEM02 0x83 ULP Memory Byte 2 Y 57
CP2400/1/2/3
38 Rev. 1.0
ULPMEM03 0x84 ULP Memory Byte 3 Y 57
ULPMEM04 0x85 ULP Memory Byte 4 Y 57
ULPMEM05 0x86 ULP Memory Byte 5 Y 57
ULPMEM06 0x87 ULP Memory Byte 6 Y 57
ULPMEM07 0x88 ULP Memory Byte 7 Y 57
ULPMEM08 0x89 ULP Memory Byte 8 Y 57
ULPMEM09 0x8A ULP Memory Byte 9 Y 57
ULPMEM10 0x8B ULP Memory Byte 10 Y 57
ULPMEM11 0x8C ULP Memory Byte 11 Y 57
ULPMEM12 0x8D ULP Memory Byte 12 Y 57
ULPMEM13 0x8E ULP Memory Byte 13 Y 57
ULPMEM14 0x8F ULP Memory Byte 14 Y 57
ULPMEM15 0x90 ULP Memory Byte 15 Y 57
LCD Control Registers
LCD0CN 0x95 LCD0 Control Y 84
CONTRAST 0x96 LCD0 Contrast Adjustment Y 85
LCD0CF 0x97 LCD0 Configuration Y 86
LCD0DIVL 0x98 LCD0 Clock Divider High Byte Y 87
LCD0DIVH 0x99 LCD0 Clock Divider Low Byte Y 87
LCD0TOGR 0x9A LCD0 Toggle Rate Y 88
LCD0PWR 0x9B LCD0 Power Mode Y 89
Ultra Low Power Control Registers
MSCN 0xA0 Master Control Y 58
MSCF 0xA1 Master Configuration Y 59
ULPCN 0xA2 Ultra Low Power Control Y 54
Port I/O Configuration Registers
P0OUT 0xB0 Port 0 Output Data Latch N 66
P1OUT 0xB1 Port 1 Output Data Latch N 66
P2OUT 0xB2 Port 2 Output Data Latch N 66
P3OUT 0xB3 Port 3 Output Data Latch N 66
P4OUT 0xB4 Port 4 Output Data Latch N 66
P0MDI 0xB5 Port 0 Input Mode N 67
P1MDI 0xB6 Port 1 Input Mode N 67
P2MDI 0xB7 Port 2 Input Mode N 67
P3MDI 0xB8 Port 3 Input Mode N 67
P4MDI 0xB9 Port 4 Input Mode N 67
P0MDO 0xBA Port 0 Output Mode N 67
P1MDO 0xBB Port 1 Output Mode N 67
P2MDO 0xBC Port 2 Output Mode N 67
P3MDO 0xBD Port 3 Output Mode N 67
Table 6.3. Internal Register Memory Map (Continued)
Register Address Description Preserved Page No.
CP2400/1/2/3
Rev. 1.0 39
P4MDO 0xBE Port 4 Output Mode N 67
P0DRIVE 0xBF Port 0 Drive Strength N 68
P1DRIVE 0xC0 Port 1 Drive Strength N 68
P2DRIVE 0xC1 Port 2 Drive Strength N 68
P3DRIVE 0xC2 Port 3 Drive Strength N 68
P4DRIVE 0xC3 Port 4 Drive Strength N 68
P0MATCH 0xC4 Port 0 Match N 64
P1MATCH 0xC5 Port 1 Match N 64
P2MATCH 0xC6 Port 2 Match N 64
P3MATCH 0xC7 Port 3 Match N 64
P4MATCH 0xC8 Port 4 Match N 64
P0MSK 0xC9 Port 0 Mask N 64
P1MSK 0xCA Port 1 Mask N 64
P2MSK 0xCB Port 2 Mask N 64
P3MSK 0xCC Port 3 Mask N 64
P4MSK 0xCD Port 4 Mask N 64
Port I/O Input an d Status Registers
PMATCHST 0xD0 Port Match Status N 63
P0IN 0xD1 Port 0 Input N 66
P1IN 0xD2 Port 1 Input N 66
P2IN 0xD3 Port 2 Input N 66
P3IN 0xD4 Port 3 Input N 66
P4IN 0xD5 Port 4 Input N 66
Table 6.3. Internal Register Memory Map (Continued)
Register Address Description Preserved Page No.
CP2400/1/2/3
40 Rev. 1.0
7. Interrupt Sources
The CP2400/1/2/3 can alert the host processor when any of the interrupt source events listed in Table 7.1 triggers
an interrupt. The CP2400/1/2/3 alerts the host of pending interrupt events by setting the appropriate flags in the
interrupt status registers and driving the INT pin low. The INT pin will remain asserted until all interrupt flags for
enabled interrupts have been cleared by the host. Interrupt flags are cleared by reading the self-clearing interrupt
status registers, INT0 and INT1. Interrupts can be disabled by clearing the corresponding bits in INT0EN and
INT1EN.
Note: When SmaRTClock interrupts are enabled, they are also captured in t he ULPST register. If the bits in ULPST are set,
then the SmaRTClock interrupt flags in the INT0 register will not clear. To clear SmaRTClock interrupt events, first clear
the ULPST register then clear INT0.
If the host processor does not utilize the INT pin, it can periodically read the interrupt status registers to determine
if any interrupt-generating events have occurred. The INT0RD and INT1RD read-only registers provide a method
of checking for interrupts without clearing the interrupt status registers.
Table 7.1. Interrupt Source Events
Event Description Pending
Flag Enable
Flag
SmaRTClock Alarm A SmaRTClock Alarm has occurred. INT0.4 INT0EN.4
SmaRTClock Oscillator Failure The SmaRTClock Oscillator has
experience d a fa ilur e. INT0.3 INT0EN.3
Port Match A Port Match event has occurred. INT0.0 INT0EN.0
Reset Complete The device is now initialized and ready to
communicate over the host interface. INT1.4 INT1EN.4
Timer 1 Overflow Timer 1 has ov erflowed from 0xF FF F to
0x0000 or a SmaR TClock capture event has
occurred.
INT1.3 INT1EN.3
Timer 0 Overflow Timer 0 has ov erflowed from 0xF FF F to
0x0000. INT1.2 INT1EN.2
CP2400/1/2/3
Rev. 1.0 41
Address = 0x43
SFR Definition 7.1. INT0: Interrupt Status Register 0 (Self-Clearing)
Bit76543210
Name Reserved ALRM RTCFAIL PMINT
Type RRRRRRRR
Reset 00000000
Bit Name Function
7:6 Unused Read = 00b.
5 Reserved Read = 0.
4ALRMSmaRTClock Alarm Interrupt Flag.
0: No SmaRTClock Alarm pending since ALRM was last cleared.
1: SmaRTClock Alarm pending.
3RTCFAILSmaRTClock Oscillator Fail Interrupt Flag.
0: No SmaRTClock oscillator failure events detected since RTCFAIL was last cleared.
1: SmaRTClock oscillator failure detected.
2:1 Unused Read = 00b.
0PMINTPort Match Interrupt Flag.
0: No Port Match events detected since PMINT was last cleared.
1: Port Match event pending.
CP2400/1/2/3
42 Rev. 1.0
Address = 0x40
SFR Definition 7.2. INT0RD: Interrupt Status Register 0 (Read-Only)
Bit7 6543210
Name Reserved ALRMR RTCFAILR PMINTR
Type R RRR RRRR
Reset 0 0000000
Bit Name Function
7:6 Unused Read = 00b.
5 Reserved Read = 0.
4ALRMRSmaRTClock Alarm Interrupt Flag.
0: No SmaRTClock Alarm pending since ALRM was last cleared.
1: SmaRTClock Alarm pending.
3RTCFAILRSmaRTClock Oscillator Fail Interrupt Flag.
0: No SmaRTClock oscillator failure events detected since RTCFAIL was last cleared.
1: SmaRTClock oscillator failure detected.
2:1 Unused Read = 00b.
0PMINTRPort Match Interrupt Flag.
0: No Port Match events detected since PMINT was last cleared.
1: Port Match event pending.
CP2400/1/2/3
Rev. 1.0 43
Address = 0x30
SFR Definition 7.3. INT0EN: Interrupt Enable Register 0
Bit76543210
Name Reserved EALRM ERTCFAIL EPMINT
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 11110111
Bit Name Function
7:6 Unused Read = 11b. Write = don’t care.
5 Reser ve d Read = varies. Write = must write 0b.
4 EALRM Enable SmaRTClock Alarm Interrupt.
This bit sets the masking of the SmaRTClock Alarm interrupt.
0: Disable SmaRTClock Alarm interrupts.
1: Enable interrupt requests generated by SmaRTClock Alarm Events.
3ERTCFAILEnable SmaRTClock Fail Interrupt.
This bit sets the masking of the SmaRTClock Oscillator Fail interrupt.
0: Disable SmaRTClock Oscillator Fail interrupt.
1: Enable interrupt requests generated by SmaRTClock Oscillator Failure.
2:1 Unused Read = 11b. Write = don’t care.
0 EPMINT Enable Port Match Interrupt.
This bit sets the masking of Port Match Interrupt.
0: Disable Port Matc h Int er ru p t.
1: Enable interrupt requests generated by Port Match events.
CP2400/1/2/3
44 Rev. 1.0
Address = 0x44
SFR Definition 7.4. INT1: Interrupt Status Register 1 (Self-Clearing)
Bit76543210
Name RSTC T1F T0F
Type RRRRRRRR
Reset 00000100
Bit Name Function
7:5 Unused Read = 000b.
4RSTCReset Complete Interrupt Flag.
0: Device has not yet finished initialization.
1: Device is ready for communication over the host interface.
3T1FTimer 1 Overflow Interrupt Flag.
0: Timer 1 has not overflowed and no capture events have occurred since T1F was last
cleared.
1: Timer 1 has overflowed or a capture event has occurred since T1F was last cleared.
2T0FTimer 0 Overflow Interrupt Flag.
0: Timer 0has not overflowed since T0F was last cleared.
1: T imer 0 has overflowed since T0F was last cleared.
1:0 Unused Read = 00b.
CP2400/1/2/3
Rev. 1.0 45
Address = 0x41
SFR Definition 7.5. INT1RD: Interrupt Status Register 1 (Read-Only)
Bit76543210
Name RSTCR T1FR T0FR
Type RRRRRRRR
Reset 00010100
Bit Name Function
7:5 Unuse d Read = 000b.
4RSTCRReset Complete Interrupt Flag.
0: Device has not yet finished initialization.
1: Device is ready for communication over the host interface.
3T1FRTimer 1 Overflow Interrupt Flag.
0: Timer 1 has not overflowed and no capture events have occurred since T1F was last
cleared.
1: Timer 1 has overflowed or a capture event has occurred since T1F was last cleared.
2T0FRTimer 0 Overflow Interrupt Flag.
0: Timer 0has not overflowed since T0F was last cleared.
1: T imer 0 has overflowed since T0F was last cleared.
1:0 Unuse d Read = 00b.
CP2400/1/2/3
46 Rev. 1.0
Address = 0x31
SFR Definition 7.6. INT1EN: Interrupt Enable Register 1
Bit76543210
Name ERSTC ET1F ET0F
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 11111111
Bit Name Function
7:5 Unused Read = 111. Write = don’t care.
4ERSTCEnable Reset Complete Interrupt.
0: Disable Reset Complete interrupt.
1: Enable interrupt re quest s generated when device is ready for communication over the host
interface.
3ET1FEnable Timer 1 Overflow Interrupt.
0: Disable Timer 1 Overflow Interrupt.
1: Enable interrupt requests generated by Timer 1.
2ET0FEnable Timer 0 Overflow Interrupt.
0: Disable Timer 0 Overflow Interrupt.
1: Enable interrupt requests generated by Timer 0.
1:0 Unused Read = 11. Write = don’t care.
CP2400/1/2/3
Rev. 1.0 47
8. Reset Sources
Reset circuitry allows the CP2400/1/2/3 to be easily placed in a predefined default condition. Upon entry to this
reset state, the following events occur:
All direct and indirect registers are initialized to their defined reset values.
Port I/O pins are forced into a high impedance state with a weak pull-up to VDD.
The INT pin is forced to a logic high state.
The internal oscillator is stopped.
All interrupts (except SmaRTClock Oscillator Fail) are enabled.
The CP2400/1/2/3 has two reset sources that place the device in the reset state. The method of entry to the reset
state determines the amount of tim e spent in reset. Each of the followin g reset sources is described in the following
sections:
Power-On
External RST Pin
Upon exit from the reset state, the device automatically starts the internal oscillator then asserts the interrupt pin.
The device is fully functional after the interrupt pin is asserted.
8.1. Reset Initialization
After every CP2400/1/2/3 reset, the following initialization procedure is recommended to ensure proper device
operation:
1. Wait for the Reset Complete Interrupt (interrupt pin assertion).
2. Disable interrupts (using INT0EN and INT1EN on page 43 and page 46) for events that will not be
monitored or handled by the host processor. By default, all interrupts except for SmaRTClock Oscilla-
tor Fail are enabled after every reset.
3. Configure the device for the intended mode of operation.
CP2400/1/2/3
48 Rev. 1.0
8.2. Power-On Reset
During power-up, the CP2400/1/2/3 is held in the reset state until VDD settles above VRST. A delay (TPORDelay)
occurs between the time VDD reaches VRST and the time the device is released from reset. Refer to Table 3.3 for
the Electrical Char ac ter i stic s of the po we r- on reset circ uit.
Figure 8.1. Reset Timing
8.3. External Pin Reset
The RST pin provides a means for extern al circuitry to for ce the CP2400/1/2/3 into a reset state. Asserting RST for
at least TRST will cause the CP2400/1/2/3 to enter the reset state. It is recommended to drive RST with a push-pull
driver or add an external pull-up resistor to avoid erroneous noise-induced resets. The CP2400/1/2/3 will exit the
reset state and generate a Reset Complete Interrupt approximately one TSTARTUP delay after a logic high is
detected on RST. Refer to Ta ble 3.3 on page 16 for the Electrical Characteristics.
Po w e r-On
Reset
/RST
t
volts
1.0
Logic HIGH
Logic LOW TPORDelay
VDD
VRST
VDD
CP2400/1/2/3
Rev. 1.0 49
9. Power Modes
The CP2400/1/2/3 has four power modes that can be used to minimize overall system power consumption. The
power modes vary in device functionality and wake- up methods. Each o f the following power modes is expla ined in
the following sections:
Normal Mode (Device Fully Functional)
RAM Preservation Mode (Internal Oscillator Disabled)
Ultra Low Power LCD Mode (Regulator Disabled )
Ultra Low Power SmaRTClock Mode (Regulator Disabled, LCD Disabled)
Shut Down Mode (All functionality Disabled)
The power modes above are achieved by disabling specific primary functions of the CP2400/1/2/3. Figure 9.1
shows how power is distributed thro ughout the CP2 400/1/2/3. Additional secondary func tions may also be d isabled
to save power. These are described in Section “9.8. Disabling Secondary Device Functions” on page 58.
Figure 9.1. Power and Clock Distribution Control
VDD
Digital Logic
ULP
LCD Control
U L P P o rt Matc h
Sm aRTClock
Inte rn a l Os c illa tor
A c tive P o r t M a tc h
LDO
SRAM
Timers
H o s t Inte rfa c e
ULP Control
Logic
CP2400/1/2/3
50 Rev. 1.0
9.1. Normal Mode
Normal mode should be used whenever the host controller is communicating with the CP2400/1/2/3. In this mode,
the device is fully functional and the host in terface is cap able of operating a t full speed. Typical normal mode power
consumption is listed in Table 3.1 on page 12.
9.2. RAM Preservation Mode
In RAM Preservation Mode, the internal oscillator is disabled and the SmaRTClock oscillator provides the system
clock. RAM Preservation Mode should be used when the CP2400/1/2/3 needs to be active for a prolonged period
of time in which communication with the host microcontroller is not required. Examples of this include preserving
the contents of RAM or using the fully featured Active port match capabilities. LCD and SmaRTClock functionality
remains fully functional in RAM Preservation Mode. Interrupt latency does increase in this mode.
From Normal Mode, the device can be placed in RAM Preservation Mode using the following procedure:
1. Drive the CLK pin LOW.
2. Write 0x07 to the IOSCCN register to synchronize the oscillator control logic.
3. Write 0x03 to the IOSCCN register to switch oscillator control to the CLK pin.
4. Write 0x05 to the CLKSL register to select SmaRTClock oscillator as the system clock.
5. Drive the CLK pin HIGH.
From RAM Preservation Mode, the device can be returned to Normal Mode using the following procedure:
1. Drive the CLK pin LOW. This will force the system clock to Internal Oscillator divided by 1.
2. Write 0x06 to the IOSCCN register to force the internal oscillator to remain enabled.
See Table 3.4 for RAM Preservation Mode wake-u p time. When using the SPI Interf ace, the CLK pin ma y be tied to
NSS in order to wake the device from RAM Pr eservation Mode on NSS falling. The CLKOVR bit (MSCN.2) must be
set to logic 0 and the SmaRTClock must be enabled and running in order to place the device in RAM Preservation
Mode.
CP2400/1/2/3
Rev. 1.0 51
9.3. Ultra Low Power LCD Mode
In Ultra Low Power LCD Mode, the on-chip LDO is placed in a low power state and power is gated off from all
digital logic residing outside the ULP block. The ULP block allows the device to refresh an LCD, maintain a real
time clock, detect SmaRTClock Alarm, SmaRTClock Oscillator Fail, and ULP Port Match events. The Port Match
functionality in ULP Mode differs from the functionality of Port Match when the device is in Normal or RAM
Preservation Mode . See Section “9.7. Port Match Functionality in the Ultra Low Powe r Modes” on p age 56 for more
details.
All Port I/O with the exception of P3.3-P4.3 must be configured to Analog mode prior to entering ULP Mode.
From Normal Mode, the device can be placed in ULP LCD Mode using the following procedure:
1. Set INT0EN:INT1EN to 0x1900. This enables the SmaRTClock Fail, SmaRTClock Alarm, and Port
Match interrupts and disables all others.
2. Configure the bandgap into one of its low power modes by writing 0xC0 or 0x80 to MSCF. Choosing
the loose bandgap regulation (MSCF = 0x80) will result in the lowest supply current at the expense of
increased ripple in the LCD output voltage.
3. Drive the PWR or NSS pin LOW.
4. Set the LCDEN (ULPCN.3) to logic 1. If Port Match functionality is desired, also set the ULPEN
(ULPCN.1) bit to logic 1.
5. Drive the PWR or NSS pin HIGH .
The device will not enter ULP mode if there are pending wake-up events, and the INT pin will remain asserted. To
ensure that the device has successfully entered the low power mode, the host processor should verify that there
are no pending wake- up events prior to placing the de vice in a ULP mode a nd that the INT pin re mains de-asserted
for 100 µs after placing the device in ULP mode. If the INT pin is found to be asserted, then the host controller
should treat the situation as if the device has entered ULP and has been awoken by a wake-up event. The state of
RAM and unpreserved registers should not be relied upon since the host controller will not be able to determine if
the regulator has been disabled and re-enabled, or never disabled. The Port Match, SmaRTClock Alarm, and
SmaRTClock Oscillator Fail interrupts should always be enabled any time the device is placed in a ULP mode.
Once the device enters ULP LCD Mode, it will remain in this low power mode until a SmaRTClock Alarm,
SmaRTClock Oscillator Fail, or ULP Port Match wake-up event occurs. Once the device wakes up, it will generate
a reset complete interrupt and assert the INT pin. The host controller may also wake up the device at any time.
To resume Normal Mode ope ra tio n, th e ho st controller should use the following procedure:
1. Drive the PWR or NSS pin LOW.
2. Wait for the INT pin to be asserted. See Table 3.4 for ULP Mode wake up time.
3. Re-initialize all registers which ar e not preser ved du ring ULP mode. See Table 6.3 for a list of registers
that preserve their state in ULP mode.
Note: The Port I/O state and configuration settings are preserved as long as the device is in the low power mode. Upon wake-
up, all Port I/O state and configuration settings will reset, making all Port I/O digital inputs with weak pullups enabled.
They will remain in this state until the host controller re-initializes the Port I/O state and configuration registers.
In the ULP LCD Mode, the SmaRTClock oscillator may be disabled if a low frequency CMOS clock (~32 kHz) is
present at CLK pin. Set the RTCBYP bit (MSCN.7) to logic 1 in order to override the SmaRTClock with the CMOS
clock available at the CLK pin. The SmaRTClock should be disabled by writing 0x00 to the indirect RTC0CN
register instead of setting the RTCDIS bit (ULPCN.4) while entering ULP LCD Mode. When the SmaRTClock is
disabled, SmaRTClock alarm and SmaRTClo ck oscillator fail detection functionality is no longer available.
CP2400/1/2/3
52 Rev. 1.0
9.4. Ultra Low Power SmaRTClock Mode
In Ultra Low Power SmaRTClock Mode, the on-chip LDO is placed in a low power state and po wer is gated of f from
all digital logic residing outside the ULP block. LCD functionality is disabled. The ULP block allows the device to
maintain a real time clock and detect SmaRTClock Alarm, SmaRTClock Oscillator Fail, and ULP Port Match
events. The Port Matc h funct ionalit y in UL P Mo de d iffers from the func tionality of Po rt Ma tch w hen the d evice is in
normal or RAM Preservation Mode. See Section “9.7. Port Match Functionality in the Ultra Low Power Modes” on
page 5 6 fo r mo re details.
From normal mode, the device can be placed in ULP SmaRTClock Mode using the following procedure:
1. Set INT0EN:INT1EN to 0x1900. This enables the SmaRTClock Fail, SmaRTClock Alarm, and Port
Match interrupts and disables all others.
2. Place the bandgap into its lowest power mode by writing 0x80 to MSCF.
3. Drive the PWR or NSS pin LOW.
4. Set the ULPEN (ULPCN.1) bit to logic 1. If port match functionality is not desired, ensure that all the
ULP Port Mask bits are set to logic 0 by writing 1 to ULPRST (ULPCN.1).
5. Drive the PWR or NSS pin HIGH .
The device will not enter any ULP mode if there are pending wake-up events, and the INT pin will remain asserted.
To ensure that the device has successfully entered the low power mode, the host processor shoul d verify tha t there
are no pending wake- up events prior to placing the de vice in a ULP mode a nd that the INT pin re mains de-asserted
for 100 us after placing the device in ULP mode. If the INT pin is found to be asserted, then the host controller
should treat the situation as if the device has entered ULP and has been awoken by a wake-up event. The state of
RAM and unpreserved registers should not be relied upon since the host controller will not be able to determine if
the regulator has been disabled and re-enabled, or never disabled. The Port Match, SmaRTClock Alarm, and
SmaRTClock Oscillator Fail interrupts should always be enabled any time the device is placed in a ULP mode.
Once the device enters ULP SmaRTClock Mode, it will re main in this low power mode until a SmaRTClock Alarm,
SmaRTClock Oscillator Fail, or ULP Port Match wake-up event occurs. Once the device wakes up, it will generate
a reset complete interrupt and assert the INT pin. The host controller may also wake up the device at any time.
To resume normal mode operation, the host controller should use the following procedure:
1. Drive the PWR or NSS pin LOW.
2. Wait for the INT pin to be asserted. See Table 3.4 for ULP Mode wake up time.
3. Re-initialize all registers which ar e not preser ved du ring ULP mode. See Table 6.3 for a list of registers
that preserve their state in ULP mode.
Note: The Port I/O state and configuration settings are preserved as long as the device is in the low power mode. Upon wake-
up, all Port I/O state and configuration settings will reset, making all Port I/O digital inputs with weak pullups enabled.
They will remain in this state until the host controller re-initializes the Port I/O state and configuration registers.
In the ULP SmaRTClock Mode, the SmaRTClock oscillator may be disabled if a low frequency CMOS clock
(~32 kHz) is present at CLK pin. Set the RTCBYP bit (MSCN.7) to logic 1 in order to override the SmaRTClock with
the CMOS clock available at the CLK pin. The SmaRTClock should be disabled by writing 0x00 to the indirect
RTC0CN register instead of setting the RTCDIS bit (ULPCN.4). When the SmaRTClock is disabled, SmaRTClock
alarm and SmaRTClock oscillator fail detection functionality is no longer available.
CP2400/1/2/3
Rev. 1.0 53
9.5. Shutdown Mode
Shutdown mode is the lowest power mode for the CP2400/1/2/3. All device functionality is disabled in this mode
and a reset is required to wake up the device. This mode is typically used when the device is not needed for
prolonged periods of time.
From Normal Mode, the device can be placed in shutdown mode using the following procedure:
1. Set INT0EN:INT1EN to 0x1900. This enables the SmaRTClock Fail, SmaRTClock Alarm, and Port
Match interrupts and disables all others.
2. Ensure that all ULP Port Mask bits are set to logic 0 by writing 1 to ULPRST (ULPCN.1).
3. Configure the bandgap for Shutdown Mode by writing 0x80 to MSCF.
4. Drive the PWR or NSS pin LOW.
5. Set the R TCDIS (ULPCN.4) and the ULPEN (ULPC N.1 ) bit to logic 1.
6. Drive the PWR or NSS pin HIGH .
The device will not enter Shutdown if there are pending wake-up events, and the INT pin will remain asserted. To
ensure that the device has successfully entered the low power mode, the host processor should verify that there
are no pending wake-up events prior to placing the device in Shutdown Mode and that the INT pin remains de-
asserted for 100 µs after placing the device in Shutdown Mode. If the INT pin is found to be asserted after the
device has been placed in Shutdown, the device should be reset and placed in shutdown again. It is essential that
all ULP Port Mask bits be set to logic 0 before the device is placed in Shut down in order to prevent the possibility of
a partial wake-up due to a Port Match event. The Port Match, SmaRTClock Alarm, and SmaRTClock Oscillator Fail
interrupts should always be enabled any time the device is placed in Shutdown mode.
Note: The Port I/O state and configuration settings are preserved as long as the device is in Shutdown. Upon reset, all Port I/O
state and configuration settings will reset, making al l Port I/O digi tal inputs with weak pull-ups enabled. They will rema in
in this state until the host controller re-initializes the Port I/O state and configuration regist ers.
CP2400/1/2/3
54 Rev. 1.0
Address = 0xA2
Note: The state of ULPPMPOL should not be changed in the same writ e which enables the ULP modes. Rather, the state of
ULPPMPOL should be set first, then the ULP mode should be enabled.
SFR Definition 9.1. ULPCN: Ultra Low Power Control Register
Bit7654321 0
Name RTCDIS LCDEN Reserved ULPEN ULPPMPOL
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0000000 0
Bit Name Function
7:5 Unused Read = 000b. Write = Don’t Care.
4RTCDISUltra Low Power Mode SmaRTClock Disable.
When set to 1, the SmaR TClock oscillator will be disabled two SmaRTClock cycles after entry
into ULP Mode. This allows the device to enter its Shutdown Mode.
Any write operation that sets this bit to 1b must also set ULPEN to 1b.
3LCDENUltra Low Power LCD Enable.
When set to 1, LCD Functionality is enabled in ULP mode. Rising edge transitions on NSS
and PWR disable the internal LDO and place the device into the ultra low power mode. A
falling edge transition on NSS or PWR will re-enable the regulator and return the device to
normal power mode. This bit is self-clearing upon wake-up from the ultra low power mode.
2 Reserved Read = 0b. Must write 0b.
1 ULPEN Ultra Low Power Port Match Enable.
When set to 1, Port Match Functionality is enabled in ULP mode. Rising edge transitions on
NSS and PWR disable the internal LDO and place the device into the ultra low power mo de. A
falling edge transition on NSS or PWR will re-enable the regulator and return the device to
normal power mode. This bit is self-clearing upon wake-up from the ultra low power mode.
0 ULPPMPOL Ultra Low Power Port Match Pola rity.
0: ULP Port Match wake-up occurs on rising edge transitions (level sensitive).
1: ULP Port Match wake-up occurs on falling edge transition s ( level sensitive).
CP2400/1/2/3
Rev. 1.0 55
9.6. Determining the ULP Mode Wake-Up Source
After waking from ULP Mode, the ULPST register may be used to determine the cause of wake up. The three pos-
sible wake up sources are SmaRTClock Alarm, SmaRTClock Oscillator Failure, and ULP Port Match. If none of the
bits in ULPST are set, then the wake up was due to the NSS or PWR pin falling edge.
This register may be cleared by writing a 1 to the CLEAR (MSCN.6) bit in the master control register.
Address = 0x42
SFR Definition 9.2. ULPST: Ultra Low Power Status Register
Bit765432 1 0
Name RTCFAIL RTCALRM ULPPM
Type RRRRRR R R
Reset 000000 0varies
Bit Name Function
7:3 Unused Read = 00000b. Write = Don’t Care.
2RTCFAILSmaRTClock Oscillator Fail Wake Up Indicator.
0: Source of last wake up was not a SmaRTClock Oscillator Fail.
1: Source of last wake up was a SmaRTClock Oscillator Fail.
1RTCALRMSmaRTClock Alarm Wake Up Indicator.
0: Source of last wake up was not a SmaRTClock Alarm.
1: Source of last wake up was a SmaRTClock Alarm.
0 ULPPM Ultra Low Power Port Match Wake Up Indicator.
0: Source of last wake up was not a ULP Port Match.
1: Source of last wake up was a ULP Port Match.
CP2400/1/2/3
56 Rev. 1.0
9.7. Port Match Functionality in the Ultra Low Power Modes
The ultra low power LCD a nd SmaRTClock modes suppo rt por t match wake -u p. ULP Sma RTClock mode supports
port match on all P0, P1, P2, and P3 pins. ULP LCD mode supports port match on P3.3, P3.4, P3.5, P3.6, and
P3.7. ULP Port Match events can be generated on rising or falling edges; however, all events are configured to the
same polarity using the ULPPMPOL bit (ULPCN.0). ULP Port Match is level sensitive and a new Port Mat ch event
will be generated every clock cycle as long as the I/O state matches the polarity set by the ULPPMPOL bit.
Note: In ULP LCD Mode, when usi ng a 4-mux LCD, port match may only be used to detect ri sing edges.
Each Port I/O that participates in ULP Port Match is individually maskable to allow or disallow the generation of
Port Match events. The most significant bit in each 4-bit nibble of ULP Memory controls the masking of a single
Port I/O. For example, the masking of P3.4 and P3.5 are controlled by bit 3 and bit 7 of ULPMEM14, respectively.
Table 9.1 and Table 9.2 show the ULP Mask bit locations for all I/O capable of port match when the device is in
ULP SmaRTClock and ULP LCD mode, respectively. A mask setting of 0 will prevent the generation of Port Match
events from the specified I/O and a mask setting of 1 will allow generation of Port Match events from the specified
I/O. Port I/O to be used for ULP Port Match must be configured as digital pins. Setting the ULPRST (ULPCN.1) to
logic 1 will reset all Port Mask bits to 0.
ULP Port Match is enabled upon entry into ULP mode when the ULPEN bit (ULPCN.1) is set to logic 1 and
disabled upon wake-up from ULP mode. The ULPST register may be used to determine when a ULP Port Match
event has occurred. When enabled, the Port Match interrupt will occur when an Active Mode Port Match or ULP
Port Match even t occur s.
Table 9.1. ULP SmaRTClock Port Match Mask Bit Locations
ULP Memory Bit 7 Masks Bit 3 Masks
ULPMEM00 P0.1 P0.0
ULPMEM01 P0.3 P0.2
ULPMEM02 P0.5 P0.4
ULPMEM03 P0.7 P0.6
ULPMEM04 P1.1 P1.0
ULPMEM05 P1.3 P1.2
ULPMEM06 P1.5 P1.4
ULPMEM07 P1.7 P1.6
ULPMEM08 P2.1 P2.0
ULPMEM09 P2.3 P2.2
ULPMEM10 P2.5 P2.4
ULPMEM11 P2.7 P2.6
ULPMEM12 P3.1 P3.0
ULPMEM13 P3.3 P3.2
ULPMEM14 P3.5 P3.4
ULPMEM15 P3.7 P3.6
Table 9.2. ULP LCD Port Match Mask Bit Locations
ULP Memory Bit 7 Masks Bit 3 Masks
ULPMEM13 P3.3 N/A
ULPMEM14 P3.5 P3.4
ULPMEM15 P3.7 P3.6
CP2400/1/2/3
Rev. 1.0 57
Addresses: ULPMEM00 = 0x81, ULPMEM01 = 0x82, ULPMEM02 = 0x83, ULPMEM03 = 0x84,
ULPMEM04 = 0x85, ULPMEM05 = 0x86, ULPMEM06 = 0x87, ULPMEM07 = 0x88,
ULPMEM08 = 0x89, ULPMEM09 = 0x8A, ULPMEM10 = 0x8B, ULPMEM11 = 0x8C,
ULPMEM12 = 0x8D, ULPMEM13 = 0x8E, ULPMEM14 = 0x8F, ULPMEM15 = 0x90.
SFR Definition 9.3. ULPMEMn: ULP Memory
Bit76543210
Name ULPMEMn
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:0 ULPMEMn ULP Memory.
Each nibble controls one I/O pin.
See “12.5. Mapping ULP Memory to LCD Pins” on page 90 for information on how ULP
Memory is used with the LCD function.
See Section “9.7. Port Match Functionality in the Ultra Low Power Modes” on page 56 for
information on how ULP Memory is used with the ULP Port Match function.
CP2400/1/2/3
58 Rev. 1.0
9.8. Disabling Secondary Device Functions
The MSCN and MSCF registers provide additional ways of savin g po we r by disab lin g un ne ce ss ar y func tion ality.
Address = 0xA0
SFR Definition 9.4. MSCN: Master Control Register
Bit765432 1 0
Name RTCBYP CLEAR ADRINV RTCOD SRAMD CLKOVR ULPRST LCDEN
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 000000 0 0
Bit Name Function
7 RTCBYP SmaRTClock Oscillator Bypass.
When set to 1, the SmaRTClock oscillator clock is bypassed and the CLK pin is used to drive
the low frequency clock used for ULP operations.
6 CLEAR ULP Status Clear.
Writing 1 to this register clears all bits in the ULP status register (ULPST).
5ADRINVSRAM Address Invert.
When set to 1, the least significant byte of the SRAM target address is inverted. This allows
the SRAM to be accessed in reverse sequential order using a single block read or write. For
example, a block read from addresses 0x0400 to 0x04FF will return data from RAM locations
0x04FF to 0x0400.
4RTCODSmaRTClock Oscillator Output Disable.
When set to 1, the SmaRTClock oscillator output is gated off, and does not drive the low
frequency clock used for ULP operations.
3SRAMDSRAM Disable.
0: The SRAM is enabled.
1: The SRAM is disabled.
2CLKOVRSyst em Clo c k Ov erride .
0: The CLKSL register determines the system clock.
1: The system clock is the CMOS clock input through the CLK pin.
1ULPRSTULP Memory Reset.
Writing 1 to this bit clears all values in the ULP Memory to 0x00. This bit can be used to
quickly set all ULP Port Mask bits to logic 0.
0LCDENLCD Enable.
0: LCD Functionality is disabled.
1: LCD Functionality is enabled.
CP2400/1/2/3
Rev. 1.0 59
Address = 0xA1
Note: When the band gap is configured for low power mode with loose voltage regulation, the LCD0CF register should be
adjusted so that charge pump cycles occur at least once every 2 ms.
SFR Definition 9.5. MSCF: Master Configuration Register
Bit765432 1 0
Name BGMD[1:0] Reserved Reserved Reserved Reserved Reserved CPBYP
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 000000 0 0
Bit Name Function
7:6 BGMD[1:0] Band Gap Power Mode.
00: Band Gap is in Normal Power Mode.
01: Reserved.
10: Band Gap is configured for low power with loose voltage regulation
(required se ttin g fo r Shu tdown Mo de ).
11: Band Gap is configured for low power with tight voltage regulation.
5:1 Reserved Read = Varies. Must write 00000b.
0 CPBYP Charge Pump Bypass.
When set to 1, the charge pump is bypassed and disabled. VDD is used as the VLCD supply
voltage.
CP2400/1/2/3
60 Rev. 1.0
10. Port Input/Output
CP2400/1/2/3 devices have 36 (48-pin packages) or 20 (32-pin packages) multi-function I/O pins. Port pins are
organized as byte-wide port s and ma y be used for ge neral purpose I/O, g eneratin g a Port Match interrupt, or for an
analog function (e.g., LCD).
Note: The port match functionality described in this chapter only applies when the device is awake (Normal and Idle Power
Modes). Refer to the Power Modes chapter for information on port match wake-up from ULP or shutdown mode.
All Port I/Os are 5 V tolerant when used as digital inputs or open-drain outputs. For Port I/Os configured as digital
push-pull outputs, current is sourced from the VDD supply. See Section 10.1 for more information on Port I/O
operating modes and the electrical specifications chapter for detailed electrical specifications. Figure shows a
block diagram of the Port I/O for the 48-pin packaged devices. The 32-pin packaged devices are functionally the
same, however, they have less I/O. Refer to the System Overview for a detailed block diagram of 32-pin devices.
Figure 10.1. Port I/O Diagram
Configuration
Registers
Port
Mapping
Logic
P0
I/O
Cells
P0.0
P0.7
(Internal Analog Signals)
36
LCD
P1
I/O
Cells
P1.0
(Port Latches -- Digital)
P2 (P0.0-P0.7)
(P3.0-P3.7)
8
8
P3
P4 (P4.0-P4.3)
4
8
PnMDO, PnMDI
Registers
P1.7
P2
I/O
Cells
P3
I/O
Cells
P4
I/O
Cells
P2.0
P2.7
P3.0
P3.7
P4.0
P4.3
4
8
8
8
P0 (P0.0-P0.7)
(P1.0-P1.7)
8
8
P1
Port Match
CP2400/1/2/3
Rev. 1.0 61
10.1. Port I/O Modes of Operation
All port pins use the Port I/O cell shown in Figure 10.2. Each Port I/O cell can be configured by software for analog
I/O or digital I/O using the PnMDI registers. On reset or wake-up from ULP mode, all Port I/O cells default to a
digital h igh impedance state with weak pull-ups enabled.
10.1.1. Port Pins Configured for Analog I/O
Any pins to be used for LCD should be configured for analog I/O (PnMDI.n = 0). When a pin is configured for
analog I/O, its weak pullup and digital output driver and receiver are disabled. Port pins configured for analog I/O
will always read back a value of 0 regardless of the actual voltage on the pin.
10.1.2. Port Pins Configured For Digital I/O
Any pins to be used for GPIO or Port Match should be configured as digital I/O (PnMDI.n = 1). For digital I/O pins,
one of two output modes (push-pull or open-drain) must be selected using the PnMDO registers.
Push-pull outputs (PnMDO.n = 1) always drive the Port pad to the VDD or GND supply rails based on the output
logic value of the Port pin. Open -drain o utput s have the high side driver disabled; th erefore, they o nly drive the Po rt
pad to GND when the output logic value is 0 and become high impedance inputs (both high and low drivers turned
off) when the output logic value is 1.
When a digit al I/O cell is pl aced in the high impedance st ate, a weak pull-up transistor pulls the Port pad to the VDD
supply voltage to ensure the digital input is at a defined logic state. Weak pullups are disabled when the I/O cell is
driven to GND to minimize power consumption. The user must ensure that digital I/O are always internally or
externally pulled or driven to a valid logic state. An analog signal applied to a digital I/O pin will result in increased
power consum p tion .
Figure 10.2. Port I/O Cell Block Diagram
GND
VDD VDD
(WEAK)
PORT
PAD
To/From Analog
Peripheral
PxMDI.x
(1 for digital)
(0 for analog)
PxOUT.x – Output
Logic Value
(Port Latch)
PxIN.x – Input Logic V alue
(Reads 0 when pin is configured as an analog I/O)
PxMDO.x
(1 for pu sh-pull)
(0 for op en-drain)
CP2400/1/2/3
62 Rev. 1.0
10.1.3. Interfacing Port I/O to 5 V and 3.3 V Logic
All Port I/Os configured for digital, open-drain operation are capable of interfacing to digital logic operating at a
supply voltage higher than 4.5 V and less than 5.25 V. When the supply voltage is in the range of 1.8 to 2.2 V, the
I/O may also interface to digital logic operating between 3.0 to 3.6 V. An external pull-up resistor to the higher
supply voltage is typically required for most systems.
Important Notes:
When interfacing to a signal that is between 4.5 and 5.25 V, the maximum clock frequency that may be in put on
a GPIO pin is 12.5 MHz. The exc ep tion to this ru le is when routing an external CMOS clock to P0.3, in which
case a signal up to 25 MHz is valid as long as the rise time (10% to 90%) is shorter than 1.8 ns.
When the supply voltage is less than 2.8 V and interfacing to a signal that is between 3.0 and 3.6 V, the
maximum clock frequency that may be input on a GPIO pin is 3.125 MHz. The exception to this rule is when
routing an external CMOS clock to P0.3, in which case a signal up to 25 MHz is valid as long as the rise time
(10% to 90%) is shorter than 1.2 ns.
In a multi-voltage interface, the external pull-up resistor should be sized to allow a current of at least 150 µA to
flow into the Port pin when the supply voltage is between (VDD_MCU/DC+ plus 0.4 V) and (VDD_MCU/DC+
plus 1.0 V). Once the Port pad voltage increas es beyo n d this range, the current flowing into the Port pin is
minimal.
These guidelines only apply to multi-volt a ge interfaces. Port I/Os may always interface to digit al log ic oper ating
at the same supply voltage.
10.1.4. Increasing Port I/O Drive Strength
Port I/O digital output drivers support a high and low drive strength; the default is low drive strength. The drive
strength of a Port I/O can be configured using the PnDR IVE re giste rs. See Table 3.2 on page 13 for the difference
in output drive strength between the two modes.
10.2. Assigning Port I/O Pins to Analog and Digital Functions
Port I/O pins are multi-function and may be used for multiple purposes. The following process can be used to
assign GPIO pins to their appropriate function.
1. Determine the pins to be used fo r the LCD function. These pins need to be configured for Analog I/O.
2. Any remaining unused pins may be used for GPIO or Port Match. These pin s need to be configur ed for Digit al I/
O. Note: ULP Port Match is only available on a limited num ber of pins. See Sec tio n “9 .7 . Port Matc h
Functionality in the Ultra Low Power Modes” on page 56 for more details. All Port
I/O with the exception of P3.3–P4.3 must be configured to Analog mode prior to entering ULP Mode.
CP2400/1/2/3
Rev. 1.0 63
10.3. Active Mode Port Match
Port match functionality allows system events to be triggered by a logic value change on a GPIO pin. A software
controlled value stored in the PnMATCH registers specifies the expected or normal logic values of the associated
Port. A Port mismatch event occurs if the logic levels of the Port’s input pins no longer match the software
controlled value. This allows software to be notified if a certain change or pattern occurs on an input pin.
The PnMSK registers can be used to individually select which pins should be compared against the PnMATCH
registers. A Port mismatch event is generated if (PnIN & PnMSK) does not equal (PnMATCH & PnMSK) for all
Ports.
A Port mismatch event may be used to generate an interrupt. See “7. Interrupt Sources” on page 40 for more
details on handling an interrup t.
Address = 0xD0
SFR Definition 10.1. PMATCHST: Port Match Status Register
Bit76543210
Name P4M P3M P2M P1M P0M
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:5 Unused Read = 000b. Write = Don’t Care.
4P4MPort 4 Match.
0: No port mismatch events have been detected on P4.
1: A port mismatch event is present on P4.
3P3MPort 3 Match.
0: No port mismatch events have been detected on P3.
1: A port mismatch event is present on P3.
2P2MPort 2 Match.
0: No port mismatch events have been detected on P2.
1: A port mismatch event is present on P2.
1P1MPort 1 Match.
0: No port mismatch events have been detected on P1.
1: A port mismatch event is present on P1.
0P0MPort 0 Match.
0: No port mismatch events have been detected on P0.
1: A port mismatch event is present on P0.
CP2400/1/2/3
64 Rev. 1.0
Address: P0MSK = 0xC9; P1MSK = 0xCA; P2MSK = 0xCB; P3MSK = 0xCC; P4MSK = 0xCD
Address: P0MATCH = 0xC4; P1MATCH = 0xC5; P2MATCH = 0xC6; P3MATCH = 0xC7; P4MATCH = 0xC8
SFR Definition 10.2. PnMSK: Port n Mask Register
Bit76543210
Name PnMSK[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 PnMSK[7:0] Port n Mask Value.
Selects the Pn pins to be compared with the corresponding bits in PnMATCH.
0: Pn.x pin pad logic value is ignored and cannot cause a Port Mismatch event.
1: Pn.x pin pad logic value is compared to PnMATCH.x.
SFR Definition 10.3. PnMATCH: Port n Match Register
Bit76543210
Name PnMATCH[7:0]
Type R/W
Reset 11111111
Bit Name Function
7:0PnMATCH[7:0]Port n Match Value.
Match comparison value used on Port n for bits whose PnMSK is set to 1.
0: Pn.x pin logic value is compared with logic LOW.
1: Pn.x pin logic value is compared with logic HIGH.
CP2400/1/2/3
Rev. 1.0 65
10.4. Registers for Accessing and Configuring Port I/O
All Port I/O are accessed and configured through registers. When writing to a Port, the value written to the PnOUT
register is latched to maintain the output data value at each pin. When reading, the logic levels of the Port's input
pins are return ed in the PnIN. If the PnOUT r egister is read , the value returned will be the value of the output latch,
not the logic level of the port pad. The PnIN register is read only.
The Port input mode of the I/O pins is defined using the Port Inpu t Mode regis ters (PnMDI ). Each Port cell can be
configured for a nalog or digit al I/O. The ou tput driver char acteristics of the digit al I/O pins are de fined using the Po rt
Output Mode registers (PnMDO). Each Port Output driver can be configured as either open drain or push-pull. To
configure a pin as a digital input, configure it as an open drain output and write 1 to its port latch.
The drive strength of the output drivers are controlled by the Port Drive Strength (PnDRIVE) registers. The default
is low drive strength. See Table 3.2 on page 13 for the difference in output drive strength be tween the two modes.
CP2400/1/2/3
66 Rev. 1.0
Address: P0OUT = 0xB0; P1OUT = 0xB1; P2OUT = 0xB2; P3OUT = 0xB3; P4OUT = 0xB4
Address: P0IN = 0xD1; P1IN = 0xD2; P2IN = 0xD3; P3IN = 0xD4; P4IN = 0xD5
SFR Definition 10.4. PnOUT: Port n Output Latch
Bit76543210
Name PnOUT[7:0]
Type R/W
Reset 11111111
Bit Name Function
7:0 PnOUT[7:0] Port n Output Latch.
Sets or reads the Port latch logic value.
0: Pn.x output latch is logic LOW.
1: Pn.x output latch is logic HIGH.
SFR Definition 10.5. PnIN: Port n Input
Bit76543210
Name PnIN[7:0]
Type R
Reset 11111111
Bit Name Function
7:0 PnIN[7:0] Port n Input.
Reads the Port pin log ic state in Port cells conf igu re d for dig ital I/O.
0: Pn.x Port pin is logic LOW.
1: Pn.x Port pin is logic HIGH.
CP2400/1/2/3
Rev. 1.0 67
Address: P0MDI = 0xB5; P1MDI = 0xB6; P2MDI = 0xB7; P3MDI = 0xB8; P4MDI = 0xB9
Address: P0MDO = 0xBA; P1MDO = 0xBB; P2MDO = 0xBC; P3MDO = 0xBD; P4MDO = 0xBE
SFR Definition 10.6. PnMDI: Port n Input Mode
Bit76543210
Name P0MDI[7:0]
Type R/W
Reset 11111111
Bit Name Function
7:0 PnMDI[7:0] Pn Analog Configuration Bits.
Port pins configured for analog mode have their weak pullup, digital driver, and digital
receiver disabled.
0: Corresponding Pn.x pin is configured for analog I/O.
1: Corresponding Pn.x pin is configured for digital I/O.
SFR Definition 10.7. PnMDO: Port n Output Mode
Bit76543210
Name PnMDO[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 PnMDO[7:0] Pn Output Configuration Bits.
0: Corresponding Pn.x Output is open-drain.
1: Corresponding Pn.x Output is push-pull.
CP2400/1/2/3
68 Rev. 1.0
Address: P0DRIVE = 0xBF; P1DRIVE = 0xC0; P2DRIVE = 0xC1; P3DRIVE = 0xC2; P4DRIVE = 0xC3
SFR Definition 10.8. PnDRIVE: Port n Drive Strength
Bit76543210
Name PnDRIVE[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 PnDRIVE[7:0] Pn Drive Strength Configuration Bits.
Configures digital I/O Port cells to high or low output drive strength.
0: Corresponding Pn.x has low output drive strength.
1: Corresponding Pn.x has high output drive strength.
CP2400/1/2/3
Rev. 1.0 69
11. SmaRTClock (Real Time Clock)
CP2400/1/2/3 devices include an u ltra low powe r 32-bit SmaR TClock Periph eral (Real Time Clock) with alarm. The
SmaRTClock has a dedicated 32 kHz oscillator that can be configured for use with or without a crystal. No external
resistor or loading capacitors are required. The on-chip loading capacitors are programmable to 16 discrete levels
allowing compatibility with a wide range of crystals.
The SmaRTClock allows a maximum of 36 hour 32-bit independent time-keeping when used with a 32.768 kHz
Watch Crystal. The SmaRTClock provides an Alarm and Missing SmaRTClock events, which could be used to
wake up from the ultra low power mode.
Figure 11.1. SmaRTClock Block Diagram
SmaRTClock Oscillator
SmaRTClock
Host Interface
XTAL2 XTAL1
RTC0CN
CAPTUREn
RTC0XCF
RTC0XCN
ALARMn
RTC0KEY
RTC0ADR
RTC0DAT
Interface
Registers
Internal
Registers
SmaRTClock State Machine
32-Bit
SmaRTC lock
Timer
Programmable Load Capacitors
Interrupt
CP2400/1/2/3
70 Rev. 1.0
11.1. SmaRTClock Interface
The SmaRTClock In terface consist s of three registers: RTCKEY, R TCADR, and R TCDAT. These interface reg isters
are located on the CP2400/1/2/3 register map and provide access to the SmaRTClock internal registers listed in
Table 11.1. The SmaRTClock internal registers can only be accessed ind irect ly th rough the Sma R TClock Interface.
11.1.1. SmaRTClock Lock and Key Functions
The SmaRTClock Interface is protected with a lock and key function. The SmaRTClock Lock and Key Register
(RTCKEY) must be written with the correct key codes, in sequence, before writes and reads to RTCADR and
RTCDAT may be performed. The key codes are: 0xA5, 0xF1. There are no timing restrictions, but the key codes
must be written in order. If the key codes are written ou t of order, the wrong cod es are written, or an indirect r egister
read or write is attempted while the interface is locked, the SmaRTClock interface will be disabled, and the
RTCADR and RTCDAT registers will become inaccessible until the next system reset. Once the SmaRTClock
interface is unlocked, software may perform any number of accesses to the SmaRTClock registers until the
interface is re-locked or the device is reset. Any write to RTCKEY while the SmaRTClock interface is unlocked will
re-lock the interface.
Reading the RTCKEY register at any time will provide the SmaRTClock Interface status and will not interfere with
the sequence that is being written. The RTCKEY register description in SFR Definition 11.1 lists the definition of
each status code.
Table 11.1. SmaRTClock Internal Registers
SmaRTClock
Address SmaRTClock
Register Register Name Description
0x00–0x03 CAPTUREn SmaRTClock Capture
Registers Four Registers used for setting the 32-bit
SmaRTClock timer or reading its current value.
0x04 RTC0CN SmaRTClock Control
Register Co ntrols the operation of the SmaRTClock S tate
Machine.
0x05 RTC0XCN SmaRTClock Oscillator
Control Register Controls the operation of the SmaRTClock
Oscillator.
0x06 RTC0XCF SmaRTClock Oscillator
Configuration Register Controls the value of the progammable
oscillator load capacitance and enables/
disables AutoStep.
0x08–0x0B ALARMn SmaRTClock Alarm
Registers Four registers used for setting or reading the
32-bit SmaRTClock al arm value.
CP2400/1/2/3
Rev. 1.0 71
11.1.2. Using RTCADR and RTCDAT to Access SmaRTClock Internal Registers
The SmaRTClock internal registers can be read and written using RTCADR and RTCDAT. The RTCADR register
selects the SmaRTClock internal register that will be targeted by subsequent reads or writes.
A SmaRTClock Write operation is initiated by writing to the RTCDAT register. Below is an example of writing to a
SmaRTClock internal register.
1. Write 0x05 to RTCADR. This selects the internal RTC0CN register at SmaRTClock Address 0x05.
2. Write 0x00 to RTCDAT. This operation writes 0x00 to the internal RTC0CN register.
A SmaRTClock Read operation is initiated by setting the SmaRTClock Interface Busy bit. This transfers the
contents of the internal register selected by RTCADR to R TCDAT. The transferred data will remain in RTCDAT until
the next read or write operation. Below is an example of reading a SmaRTClock internal register.
1. Write 0x05 to RTCADR. This selects the internal RTC0CN register at SmaRTClock Address 0x05.
2. Write 1 to BUSY. This initiates the transfer of data from RTC0CN to RTCDAT. Note: Step 1 and Step 2
may be combined into a single write.
3. Read data from RTCDAT. This data is a copy of the RTC0CN register.
11.1.3. SmaRTClock Interface Autoread Feature
When Autoread is enabled, each read from RTCDAT initiates the next indirect read operation on the SmaRTClock
internal register selected by RTCADR. Software should set the BUSY bit once at the beginning of each series of
consecutive reads. Software must check if the SmaRTClock Interface is busy prior to reading RTCDAT. Autoread is
enabled by setting AUTORD (RTCADR.6) to logic 1.
11.1.4. RTCADR Autoincrement Feature
For ease of reading and writing the 32-bit CAPTURE and ALARM values, RTCADR automatically increments after
each read or write to a CAPTUREn or ALARMn register. This speeds up the process of setting an a lar m or r eading
the current SmaRTClock timer value by allowing all 4 CAPTURE or ALARM registers to be read or written in a
single block write. Autoincrement is always enabled.
Notes: Autoincrement should only be used with block reads/wri tes. When using single-byte reads/writes, RTCADR must be
written before each data read or write.
When using SMBus to perform a block read/write, the RTCADR register must be written using the REGSET command.
CP2400/1/2/3
72 Rev. 1.0
Address = 0x0A
SFR Definition 11.1. RTCKEY: SmaRTClock Lock and Key
Bit76543210
Name RTC0ST[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 RTC0ST SmaRTClock Interface Lock/Key and Status.
Locks/unlocks the SmaRTClock interface when written. Provides lock status when read.
Read:
0x00: SmaRTClock Interface is locked.
0x01: SmaRTClock Interface is locked.
First key code (0xA5) has been written, waiting for second key code.
0x02: SmaRTClock Interface is unlocked.
First and second key codes (0xA5, 0xF1) have be en written.
0x03: SmaRTClock Interface is disabled until the next system reset.
Write:
When RTC0ST = 0x00 (locked), writing 0xA5 followed by 0xF1 unlocks the SmaRT-
Clock Interface.
When RTC0ST = 0x01 (waiting for second key code), writing any value other than the
second key code (0xF1) will change RTC0STA TE to 0x03 and disable the SmaR TClock
Interface until the next system reset.
When RTC0ST = 0x02 (unlocked), any write to RTCKEY will lock the SmaRTClock
Interface.
When RTC0ST = 0x03 (disabled), writes to RTCKEY have no ef fect.
CP2400/1/2/3
Rev. 1.0 73
Address = 0x0B
Address = 0x0C
SFR Definition 11.2. RTCADR: SmaRTClock Address
Bit76543210
Name BUSY AUTORD SHORT ADDR[3:0]
Type R/W R/W R R/W R/W
Reset 0 0 0 0 varies varies varies varies
Bit Name Function
7BUSYSmaRTClock Interface Busy Indicator.
Indicates SmaRTClock interface status. Writing 1 to this bit initiates an indirect read.
6AUTORDSmaRTClock Interface Autoread Enable.
Enables/disables Autoread.
0: Autoread Disabled.
1: Autoread Enabled.
5 Unused Read = 0b; Write = Don’t Care.
4SHORTShort Strobe Enable.
Enables/disables the Short Strobe Feature. It is recommended to always enable the short
strobe feature to minimize the read/write time.
0: Short Strobe disabl ed .
1: Short Strobe enab le d.
3:0 ADDR[3:0] SmaRTClock Indirect Register Address.
Sets the currently selected SmaRTClock register.
See Table 11.1 for a listing of all SmaRTClock indirect registers.
Note: The ADDR bits increment after each indirect read/write operation that targets a CAPTUREn or ALARMn internal
SmaRTClock register. Autoincrement should only be used with block reads/writes.
SFR Definition 11.3. RTCDAT: SmaRTClock Data
Bit76543210
Name RTCDAT[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 RTCDAT SmaRTClock Data Bits.
Holds data transferred to/from the internal SmaRTClock register selected by RTCADR.
CP2400/1/2/3
74 Rev. 1.0
11.2. SmaRTClock Clocking Sources
The SmaRTClock peripheral is clocked from its own tim ebase , in depend en t of the system clock. Th e SmaRTClock
timebase is derived from the SmaRTClock oscillator c ircuit, which has two modes of operation: crystal mode, and
self-oscillate mode. The oscillation frequency is 32.768 k Hz in crystal mode and can be programmed in the range
of sub 20 kHz to above 40 kHz in self-oscillate mode. In crystal mode, XTAL1 and XTAL2 may be overdriven by an
external CMOS clock.
11.2.1. Using the SmaRTClock Oscillator with a Crystal or External CMOS Clock
When using crystal mode, a 32.768 kHz crystal should be connected between XTAL3 and XTAL4. No other
external components are required. The following steps show how to start the SmaRTClock crystal oscillator in
software:
1. Set SmaRTClock to Crystal Mode (XMODE = 1).
2. Optional. Enable/Disable Automatic Gain Control (AGCEN) and Bias Doubling (BIASX2). See Section 11.2.4 for
recommendations on using these oscillator features.
3. Set the desired loading capacitance (R TC0XCF).
4. Enable power to the SmaRTClock oscillator circuit (RTC0EN = 1).
5. Wait 2 ms.
6. Poll the SmaRTClock Clock Valid Bit (CLKVLD) until the crystal oscillator stabilizes.
7. Poll the SmaRTClock Load Capacitance Ready Bit (LOADRDY) until the load capacitance reaches its
programmed value.
8. Enable the Sma RTClock missing clock detector.
9. Wait 2 ms.
10.Clear the PMU0CF wake-up source flags.
In crystal mode, the SmaR TClock oscillator may be driven by an external CMOS clock. The CMOS clock should be
applied to both XTAL1 and XTAL2. The input low voltage (VIL) and input high voltage (VIH) for these pins when
used with an external CMOS clock are 0.1 and 0.8 V, respectively. The SmaRTClock oscillator should be
configured to its lowest bias setting with AGC disabled. The CLKVLD bit is indeterminate when using a CMOS
clock, however, the OSCFAIL bit may be checked 2 ms after SmaRTClock oscillator is powered on to ensure that
there is a valid clock.
11.2.2. Using the SmaRTClock Oscillator in Self-Oscillate Mode
The following steps show how to configure SmaRTClock for use in self-oscillate mode:
1. Set SmaRTClock to Self-Oscillate Mode (XMODE = 0).
2. Set the desired oscillation frequency:
For oscillation at about 20 kHz, set BIASX2 = 0.
For oscillation at about 40 kHz, set BIASX2 = 1.
3. The oscillator starts oscillating instantaneously.
4. Fine tune the oscillation frequency by adjusting the load capacitance (R TC0XCF).
CP2400/1/2/3
Rev. 1.0 75
11.2.3. Programmable Load Cap acitance
The programmable load capacitance has 16 values to support crystal oscillators with a wide range of
recommended load capacitance. If Automatic Load Capacitance Stepping is enabled, the crystal load capacitors
start at the smallest setting to allow a fast startup time, then slowly increase the capacitance until the final
programmed value is reached. The final programme d loading capacitor value is specified using the LOADCAP bits
in the RTC0XCF register. The LOADCAP setting specifies the amount of on-chip load capacitance and does not
include any stray PCB capacitance. Once the final programmed loading cap a citor va lue is r eached, th e L OADRDY
flag will be set by hardware to logic 1.
When using the SmaRTClock oscillator in self-oscillate mode, the programmable load capacitance can be used to
fine tune the oscillation frequency. In most cases, increasing the load capacitor value will result in a decrease in
oscillation frequency.
.Table 11.2 shows the crystal load capacitance for various settings of LOADCAP.
Table 11.2. SmaRTClock Load Capacitance Settings
LOADCAP Crystal Load Capacitance Equivalent Capacitance seen on
XTAL1 and XTAL2
0000 4.0 pF 8.0 pF
0001 4.5 pF 9.0 pF
0010 5.0 pF 10.0 pF
0011 5.5 pF 11.0 pF
0100 6.0 pF 12.0 pF
0101 6.5 pF 13.0 pF
0110 7.0 pF 14.0 pF
0111 7.5 pF 15.0 pF
1000 8.0 pF 16.0 pF
1001 8.5 pF 17.0 pF
1010 9.0 pF 18.0 pF
1011 9.5 pF 19.0 pF
1100 10.5 pF 21.0 pF
1101 11.5 pF 23.0 pF
1110 12.5 pF 25.0 pF
1111 13.5pF 27.0pF
CP2400/1/2/3
76 Rev. 1.0
11.2.4. Automatic Gain Control and SmaRTClock Bias Doubling
Automatic Gain Control allows the SmaRTClock oscillator to trim the oscillation amplitude of a crystal in order to
achieve the lowest possible power consumption. Automatic Gain Control automatically detects when the oscillation
amplitude has reached a point where it safe to reduce the drive current, therefore, it may be enabled during crystal
startup. It is recommended to enable Automatic Gain Control in any system which uses the SmaRTClock oscillator
in crystal mode.
Turning off Automatic Gain Control will allow the crystal drive strength after oscillation is started to remain at the
same level used for starting the crystal. This will result in increased power consumption, however the crystal will
have higher immunity against external factors.
Note: Automatic Gain Control may be turned on in self-osci llate mode to reduce the oscillation fre quency and the supply cur-
rent.
The SmaRTClock Bias Doubling feature allows the self-oscillation frequency to be increased (almost doubled) and
allows a higher crystal drive strength in crystal mode. High crystal drive strength is recommended when using a
crystal with a high ESR and high loading capacitance. Table 11.3 shows a summary of the oscillator operating
modes and allowed operating conditions. SmaRTClock Bias Doubling is enabled by setting BIASX2 (RTC0XCN.5)
to 1.
Table 11.3. SmaRTClock Bias Settings and Allowed Operating Conditions
Mode Setting Power
Consumption Allowed Operat ing Condition
Crystal Bias Double Off, AGC On Lowest ESR < 40 k, any load
ESR < 50 k, Cload < 10 pF
ESR < 80 k, Cload < 8 pF
Bias Double Off, AGC Off Low ESR < 80 k, Clo ad < 10 pF
Bias Double On, AGC On High ESR < 50 k, any load
ESR < 80 k, Cload < 10 pF
Bias Double On, AGC Off Highest This mode is only recommended for
debugging purposes due to its increased
power consumption.
Self-Oscillate Bias Double Off Low 20 kHz
Bias Double On High 40 kHz
CP2400/1/2/3
Rev. 1.0 77
11.2.5. Missing SmaRTClock Detector
The missing SmaRTClock detector is a one-shot circuit enabled by setting MCLKEN (RTC0CN.6) to 1. When the
SmaRTClock Missing Clock Detector is enabled, OSCFAIL (RTC0CN.5) is set by hardware if SmaRTClock
oscillator remains high or low for more than 100 µs.
A SmaRTClock Missing Clock detector timeout can trigger an interrupt and wake the device from a low power
mode. See Section “7. Interrupt Sources” on page 40 and Section “9. Power Modes” on page 49, and for more
information.
Note: The SmaRTClock Missing Clock Detector should be disabled when making changes to the oscillator settings in
RTC0XCN.
11.2.6. SmaRTClock Oscillator Crystal Valid Detector
The SmaRTClock oscillator crystal valid detector is an oscillation amplitude detector circuit used during crystal
startup to determine when oscillation has started and is nearly stable. The output of this detector can be read from
the CLKVLD bit (RTX0XCN.4).
Notes:The CLKVLD bit has a blanking interval of 2 ms. During the fi rst 2 ms after turning on the crystal oscillator, the output of
CLKVLD is not valid.
This SmaRTClock crystal valid detector (CLKVLD) is not intended for detecting an oscillator failure. The missing
SmaRTClock detector (CLKFAIL) should be used for this purpose.
11.3. SmaRTClock Timer and Alarm Function
The SmaRTClock timer is a 32-bit counter that, when running (RTC0TR = 1), is incremented every SmaRTClock
oscillator cycle. The timer has an alarm func tion that can be set to generate an interrupt and wake the device from
a low power mode. See Section “7. Interrupt Sources” on page 40 and Section “9. Power Modes” on page 49 more
information.
The SmaRTClock timer includes an Auto Reset feature, which automatically resets the timer to zero one
SmaRTClock cycle after an alarm occurs. When using Auto Reset, the Alarm match value should always be set to
1 count less than the desired match value. Auto Reset can be enabled by writing a 1 to ALRM (RTC0CN.2).
11.3.1. Setting and Reading the SmaRTClock Timer Value
The 32-bit SmaRTClock timer can be set or read using the six CAPTUREn internal registers. Note that the timer
does not need to be stopped before reading or setting its value. The following steps can be used to set the timer
value: 1. Write the desired 32-bit set value to the CAPTUREn registers.
2. Write 1 to RTC0SET. This will transfer the contents of the CAPTUREn registers to the SmaRTClock
timer.
3. Operation is complete when RTC0SET is cleared to 0 by hardware.
The following steps can be used to read the current timer value:
1. Write 1 to RTC0CAP. This will transfer the contents of the timer to the CAPTUREn registers.
2. Poll RTC0CAP until it is cleared to 0 by hardware.
3. A snapshot of the timer value can be read from the CAPTUREn registers
11.3.2. Setting a SmaRTClock Alarm
The SmaRTClock alarm function compares the 32-bit value of SmaRTClock Timer to the value of the ALARMn
registers. An alarm event is triggered if the SmaRTClock timer is equal to the ALARMn registers. If Auto Reset is
enabled, the 32-bit timer will be cleared to zero one SmaRTClock cycle after the alarm event.
The SmaRTClock alarm event can be configured to generate a wake-up from a low power mode, or generate an
interrupt. See Section “7. Interrupt Sources” on page 40, Section “9. Power Modes” on page 49, and for more
information.
The following step s can be used to set up a SmaRTClock Alarm:
CP2400/1/2/3
78 Rev. 1.0
1. Disable SmaRTClock Alarm Events (RTC0AEN = 0) .
2. Set the ALARMn registers to the desired value.
3. Enable SmaRTClock Alarm Events (RTC0AEN = 1).
Notes:The ALRM bit, which is used as the SmaRTClock Alarm Event fl ag, is cleared by disabling SmaRTClock Alarm Events
(RTC0AEN = 0).
Disabling (RTC0AEN = 0) then re-enabling Alarm Events (RTC0AEN = 1) after a SmaRTClock Alarm without modifying
ALARMn registers will automatically schedule the next alarm after 2^32 SmaRTClock cycles (approximately 36 hours
using a 32.768 kHz crystal).
The SmaRTClock Alarm Event flag will remain asserted for a maximum of on e SmaRTClock cycle. The Alarm Event
however will be captured by the interrupt logic and will post a non-transient interrupt.
11.3.3. Software Considerations for us ing the SmaRTClock Timer and Alarm
The SmaRTClock timer and alarm have two operating modes to suit varying applications. The two modes are
described below:
Mode 1:
The first mode uses the SmaRTClock timer as a perpetual timebase which is never reset to zero. Every 36 hours,
the timer is allowed to overflow without being stopped or disrupted. The alarm interval is software managed and is
added to the ALRMn registers by software after each alarm. This allows the alarm match value to always stay
ahead of the timer by one software managed interval. If software uses 32-bit unsigned addition to increment the
alarm match value, then it does not need to handle overflows since both the timer and the alarm match value will
overflow in the same manner.
This mode is ideal for applications which have a long alarm interval (e.g., 24 or 36 hours) and/or have a need for a
perpetual timebase. An example of an application that needs a perpetual timebase is one whose wake-up interval
is constantly changing. For these applications, software can keep track of the number of timer overflows in a 16-bit
variable, extending the 32-bit (36 hour) timer to a 48-bit (272 year) perpetual timebase.
Mode 2:
The second mode uses the SmaRTClock timer as a general purpose up counter which is auto reset to zero by
hardware after each alarm. The alarm interval is managed by hardware and stored in the ALRMn registers.
Software only needs to set the alarm interval once during device initialization. After each alarm, software should
keep a count of the number of alarms that have occurred in or der to keep track of time.
This mode is ideal for applications that require minimal software intervention and/or have a fixed alarm interval.
This mode is the most power efficient since it requires less CPU time per alarm.
CP2400/1/2/3
Rev. 1.0 79
SmaRTClock Address = 0x04
Internal Register Definition 11.4. RTC0CN: SmaRTClock Control
Bit76543210
Name RTC0EN MCLKEN OSCFAIL RTC0TR RTC0AEN ALRM RTC0SET RTC0CAP
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00Varies00000
Bit Name Function
7RTC0ENSmaRTClock Enable.
Enables/disables the SmaRTClock oscillator and associated bias currents.
0: SmaRTClock oscillator disabled.
1: SmaRTClock oscillator enabled.
6MCLKENMissing SmaRTClock Detector Enable.
Enables/disables the missing SmaRTClock detector.
0: Missing SmaRTClock detector disabled.
1: Missing SmaRT Clock detector enabled.
5OSCFAILSmaRTClock Oscillator Fail Event Flag.
Set by hardware when a missing SmaRTClock detector timeout occurs. Must be cleared by
software. The value of this bit is not defined when the SmaRTClock
oscillator is disabled.
4RTC0TRSmaRTClock Timer Run Control.
Controls if the SmaRTClock timer is running or stopped (holds current value).
0: SmaRTClock tim er is stopped.
1: SmaRTClock timer is running.
3 RTC0AEN SmaRTClock Alarm Enable.
Enables/disables the SmaRTClock alarm function. Also clears the ALRM flag.
0: SmaRTClock alarm disabled.
1: SmaRTClock alarm enabled.
2ALRMSmaRTClock Alarm Event
Flag and Auto Reset Enable
Reads return the state of the
alarm event f lag .
Writes enable/disable the
Auto Reset function.
Read:
0: SmaRTClock alarm ev en t
flag is de-asserted.
1: SmaRTClock alarm ev en t
flag is asserted.
Write:
0: Disable Auto Reset.
1: Enable Auto Reset.
1 RTC0SET SmaRTClock Timer Set.
Writing 1 initiates a SmaRTClock timer set operation. This bit is cleared to 0 by hardware to
indicate that the timer set operation is complete.
0RTC0CAPSmaRTClock Timer Capture.
Writing 1 initiates a SmaRTClock timer capture operation. This bit is cleared to 0 by hardware
to indicate that the timer capture operation is complete.
Note: The ALRM flag will remain asserted for a maximum of one SmaRTClock cycle.
CP2400/1/2/3
80 Rev. 1.0
SmaRTClock Address = 0x05
Internal Register Definition 11.5. RTC0XCN: SmaRTClock Oscillator Control
Bit76543210
Name AGCEN XMODE BIASX2 CLKVLD
Type R/WR/WR/WRRRRR
Reset 00000000
Bit Name Function
7AGCENSmaRTClock Oscillator Automatic Gain Control (AGC) Enable.
0: AGC disabled.
1: AGC enabled.
6XMODESmaRTClock Oscillator Mode.
Selects Crystal or Self Oscillate Mode.
0: Self-Oscillate Mode selected.
1: Crystal Mode selected.
5 BIASX2 SmaRTClock Oscillator Bias Double Enable.
Enables/disables the Bias Double feature.
0: Bias Double disabled.
1: Bias Double enabled.
4 CLKVLD SmaRTClock Oscillator Crystal Valid Indicator.
Indicates if oscillation amplitude is sufficient for maintaining oscillation.
0: Oscillation has not started or oscillation amplitude is too low to maintain oscillation.
1: Sufficient oscillation amplitude detected.
3:0 Unuse d Read = 0000b; Write = Don’t Care.
CP2400/1/2/3
Rev. 1.0 81
SmaRTClock Address = 0x06
Internal Register Definition 11.6. RTC0XCF: SmaRTClock Oscillator Configuration
Bit7 6 5 43210
Name AUTOSTP LOADRDY LOADCAP
Type R/W R R R R/W
Reset 0 0 0 00000
Bit Name Function
7AUTOSTPAutomatic Load Capacitance Stepping Enable.
Enables/disables automatic load capacitance stepping.
0: Load capacitance stepping disabled.
1: Load capacitance stepping enabled.
6 LOADRDY Load Capacitance Ready Indicator.
Set by hardware when the load capacitance ma tches the programmed value.
0: Load capacitance is currently stepping.
1: Load capacitance has reached it programmed value.
5:4 Unused Read = 00b; Write = Don’t Care.
3:0 LOADCAP Load Capacitance Programmed Value.
Holds the user’s desired value of the load capacitance. See Table 11.2 on page 75.
CP2400/1/2/3
82 Rev. 1.0
SmaRTClock AddressCAPTURE0 = 0x00; CAPTURE1 = 0x01; CAPTURE2 =0x02; CAPTURE3: 0x03.
SmaRTClock AddressALARM0 = 0x08; ALARM1 = 0x09; ALARM2 = 0x0A; ALARM3 = 0x0B
Internal Register Definition 11.7. CAPTUREn: SmaRTClock Timer Capture
Bit76543210
Name CAPTURE[31:0]
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:0 CAPTURE[31:0] SmaRTClock Timer Capture.
These 4 registers (CAPTURE3–CAPTURE0) are used to read or set the 32-bit SmaRT-
Clock timer. Data is transferred to o r from th e SmaRTClock timer when the RTC0SET or
RTC0CAP bits are set.
Note: The least significant bit of the timer capture value is in CAPTURE0.0.
Internal Register Definition 11.8. ALARMn: SmaRTClock Alarm Programmed Value
Bit76543210
Name ALARM[31:0]
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:0 ALARM[31:0] SmaRTClock Alarm Programmed Value.
These 4 registers (ALARM3–ALARM0 ) are used to set an alarm event for the SmaR TClock
timer. The SmaRTClock alarm should be disabled ( RTC0 AEN=0) when updating these reg-
isters.
Note: The least significant bit of the alarm programmed value is in ALARM0.0.
CP2400/1/2/3
Rev. 1.0 83
12. LCD Segment Driver
CP2400/1/2/3 devices contain an LCD segment driver and on-chip bias generation that supports static, 2-mux, 3-
mux and 4-mux LCDs with 1/2 or 1/3 bias. The on-chip charge pump with programmable output voltage allows
software contrast control which is independent of the VDD supply voltage. LCD timing is derived from the
SmaRTClock oscillator to allow precise control over the refresh rate. A low frequency clock present on the CLK pin
may also be used as the LCD clock source.
The CP2400/1/2/3 contains on-chip ULP memory to store the enabled/disabled state of individual LCD segments.
All LCD waveforms are generated on-chip and software only needs to access the ULP memory to change the
information displayed on the LCD. An LCD blinking function is also supported. A block diagram of the LCD
segment driver is shown in Figure 12.1.
Figure 12.1. LCD Segment Driver Block Diagram
12.1. Initializing the LCD Segment Driver
The following procedure is recommended for using the LCD Segment Driver:
1. Configure the LCD size, mux mode, and bias using the LCD0CN register.
2. Configure the Port I/O pins to be used for LCD as Analog I/O.
3. Set the LCD contrast using the CONTRAST register.
4. Write the reserved value of 0x9F to LCD0CF.
5. Set the LCD refresh rate using the LCD0DIVH:LCD0DIVL registers.
6. Set the LCD toggle rate using the LCD0TOGR register.
7. Set the LCD power mode using the LCD0PWR register.
8. Write a pattern to the ULP memory.
9. Enable the LCD using the master control (MSCN) register.
LCD Segment Driver
VDD
Charge
Pump
CAP
10 uF
Bias
Generator
ULP Memory
Port
Drivers
Segme nt
Pins
4 CO M Pins
LCD State Machine
Configuration
Registers
CPBYP
SmaRTClock
CLK
XTAL1
XTAL2
RTCBYP
CP2400/1/2/3
84 Rev. 1.0
12.2. LCD Configuration
The LCD segment driver supports multiple mux options: static, 2-mux, 3-mux, and 4-mux mode. It also supports
1/2 and 1/3 bias options. The desired mux mode and bias is configured thro ug h th e LC D0CN register.
Address = 0x95
SFR Definition 12.1. LCD0CN: LCD0 Control Register
Bit76543210
Name BLANK SIZE MUXMD BIAS
Type R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:5 Unused Read = 000. Write = Don’t Care.
4BLANK Blank All Segm ents.
Blanks all LCD segments using a single bit.
0: All LCD segments are controlled by the LCD memory.
1: All LCD segments are blank (turned off).
3SIZE LCD Size Select.
Selects whether 16 or 32 segment pins will be used for the LCD function.
0: P0 and P1 are used as LCD segment pins.
1: P0, P1, P2, and P3 are used as LCD segment pins.
2:1 MUXMD[1:0] LCD Bias Power Mode.
Selects the mux mode.
00: Static mode selected.
01: 2-mux mode selected.
10: 3-mux mode selected.
11: 4-mux mode selected.
0BIAS Bias Select.
Selects between 1/2 Bias and 1/3 Bias.
0: LCD0 is configured for 1/3 Bia s.
1: LCD0 is configured for 1/2 Bia s.
CP2400/1/2/3
Rev. 1.0 85
12.3. LCD Bias Generation and Contrast Adjustment
The LCD Bias voltages are generated using the on-chip charge pump with programmable output voltage. The
programmable outp ut voltage allows software co ntrast cont ro l in 60 mV steps from 2.6 to 3.4 4 V. The LCD contrast
is controlled by the CONTRAST register.
Note: An external 4.7 µF decoupling capacitor is required (10 µF recommended) on the CAP pin to create a charge reservoir
at the output of the charge pump.
Intermediate voltages used for 1/2 and 3/4 bias configurations are generated on-chip using a novel approach that
allows driving extra large LCD segments while maintaining ultra low power consumption . This eliminat es the need
for off-chip biasing when driving a large LCD. The LCD drive capability can be set using the LCD0PWR register.
The highest power setting should be used for extra large LCDs (which require charging the largest capacitance)
and the lowest power setting should be used with small LCDs (smaller than 1 inch).
Address = 0x96
SFR Definition 12.2. CONTRAST: Contrast Adjustment
Bit76543210
Name CNTRST
Type R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:4 Unused Read = 0000. Write = Don’t Care.
3:0 CNTRST Contrast Adjustment.
Selects the on-chip charge pump output voltage.
0000: 2.60 V
0001: 2.60 V
0010: 2.66 V
0011: 2.72 V
0100: 2.78 V
0101: 2.84 V
0110: 2.90 V
0111: 2.96 V
1000: 3.02 V
1001: 3.08 V
1010: 3.14 V
1011: 3.20 V
1100: 3.26 V
1101: 3.32 V
1110: 3.38 V
1111: 3.44 V
CP2400/1/2/3
86 Rev. 1.0
Address = 0x97
SFR Definition 12.3. LCD0CF: LCD Configuration
Bit76543210
Name Reserved CPCYC[5:0]
Type R/W R/W
Reset 10011111
Bit Name Function
7:4 Reserved Read = 10b. Must Write 10b.
5:0 CPCYC[5:0] Charge Pump Cycle Period.
The number of SmaRTClock oscillator periods between charge pump cycles is
CPCYC[5:0]+1. The time between charge pump cycles should not exceed 2 ms.
CP2400/1/2/3
Rev. 1.0 87
12.4. LCD Timing Generation
All LCD timing is derived from the SmaRTClock oscillator divided by 2. The LCD0DIVH:LCD0DIVL registers store
the prescaler for generating the LCD refresh rate. The LCD mux mode must be taken into account when
determining the prescaler value. See the LCD0DIVH/LCD0DIVL register descriptions for more details. For
maximum power savings, choose a slow LCD refresh rate. For the least flicker, choose a fast LCD refresh rate.
Address = 0x98
Address = 0x99
SFR Definition 12.4. LCD0DIVH: LCD Refresh Rate Prescaler High Byte
Bit76543210
Name LCD0DIV[9:8]
Type R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:2 Unused Read = 000000. Write = Don’t Care.
1:0 LCD0DIV[9:8] LCD Refresh Rate Prescaler.
Sets the LCD refresh rate according to the following equation:
SFR Definition 12.5. LCD0DIVL: LCD Refresh Rate Prescaler Low Byte
Bit76543210
Name LCD0DIV[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 LCD0DIV[7:0] LCD Refresh Rate Prescaler.
Sets the LCD refresh rate according to the following equation:
LCD Refresh Rate SmaRTClo ck Oscillator Frequency
4 mux_mode
LCD0DIV 1+
--------------------------------------------------------------------------------------------=
LCD Refresh Rate SmaRTClo ck Oscillator Frequency
4 mux_mode
LCD0DIV 1+
--------------------------------------------------------------------------------------------=
CP2400/1/2/3
88 Rev. 1.0
Address = 0x9A
SFR Definition 12.6. LCD0TOGR: LCD Toggle Rate
Bit76543210
Name TOGR[3:0]
Type R/WR/WR/WR/W R/W
Reset 00000000
Bit Name Function
7:4 Unused Read = 0000. Write = Don’t Care.
3:0 TOGR[3:0] LCD Toggle Rate Divider.
Sets the LCD Toggle Rate according to the following equation:
0000: Reserved.
0001: Reserved.
0010: Toggle Rate Divider is set to divid e by 2.
0011: Toggle Rate Di vider is set to divide by 4.
0100: Toggle Rate Divider is set to divid e by 8.
0101: Toggle Rate Divider is set to divide by 16.
0110: Toggle Rate Divider is set to divide by 32.
0111: Toggle Rate Divider is set to divide by 64.
1000: Toggle Rate Divider is set to divide by 128.
1001: Toggle Rate Divider is set to divide by 256.
1010: Toggle Rate Divider is set to divide by 512.
1011: Toggle Rate Di vider is set to divide by 1024.
1100: Toggle Rate Divider is set to divide by 2048.
1101: Toggle Rate Divider is set to divide by 4096.
All other values reserved.
LCD Toggle Rate Refresh Rat e mux_mod e 2
Toggle Rate Divider
---------------------------------------------------------------------------------=
CP2400/1/2/3
Rev. 1.0 89
Address = 0x9B
SFR Definition 12.7. LCD0PWR: LCD0 Power Register
Bit76543210
Name CPCLK[1:0]
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:5 Reserved Read = 000b. Must Write 000b.
4:3 CPCLK[1:0] Charge Pump Clock Select.
00: 1 MHz charge pum p clo ck (n or ma l op eration).
01: 2 MHz charge pump clock.
10: 0.5 MHz charg e pu m p clo ck.
11: 0.67 MHz charge pump clock.
2:0 Reserved Read = 000b. Must Write 000b.
CP2400/1/2/3
90 Rev. 1.0
12.5. Mapping ULP Memory to LCD Pins
The ULP memory is organized in 16 bytes (32 half-bytes or nibbles), each nibble controlling 1 LCD output pin.
Each LCD output pin can control 1 to 4 LCD segments depending on the selected mux mode. The least significant
bit of each nibble controls the segment connected to the backplane signal COM0 and the most significant bit of
each nibble controls the segment connected to the backplane signal COM3. In static mode, only COM0 is used
and the three remaining bits in each nibble are ignored. In 4-mux mode, each bit controls an LCD segment. Bits
with a value of 1 turn on the associated segment and bits with a value of 0 turn off the associated segment.
Figure 12.2. ULP Memory Map
ULPMEM15
(P ins: LCD 31, LCD 30)
ULPMEM14
(P ins: LCD 29, LCD 28)
ULPMEM13
(P ins: LCD 27, LCD 26)
ULPMEM12
(P ins: LCD 25, LCD 24)
ULPMEM11
(P ins: LCD 23, LCD 22)
ULPMEM10
(P ins: LCD 21, LCD 20)
ULPMEM09
(P ins: LCD 19, LCD 18)
ULPMEM08
(P ins: LCD 17, LCD 16)
ULPMEM07
(P ins: LCD 15, LCD 14)
ULPMEM06
(P ins: LCD 13, LCD 12)
ULPMEM05
(P ins: LCD 11, LCD 10)
ULPMEM04
(Pins: LC D9 , LCD 8)
ULPMEM03
(Pins: LC D7 , LCD 6)
ULPMEM02
(Pins: LC D5 , LCD 4)
ULPMEM01
(Pins: LC D3 , LCD 2)
ULPMEM00
(Pins: LC D1 , LCD 0)
COM0
COM1
COM2
COM3
COM0
COM1
COM2
COM3
01234567Bit:
CP2400/1/2/3
Rev. 1.0 91
12.6. Blinking LCD Segments
The LCD driver supports blinking LCD applications such as clock applicat ions wher e the “col on” separator to ggles
on and off once per second. If the LCD is only displaying the hours and minutes, then the device only needs to
wake up once per minute to update the display. The once per second blinking is automatically handled by the
CP2400/1/2/3.
The LCD0BLINK register can be used to enable blinking on any LCD segment connected to the LCD0 or LCD1
segment pin. In static mode, a maximum of 2 segments can blink. In 4-mux mode, a maximum of 8 segments can
blink. The LCD0BLINK mask register targets the same LCD segments as the ULPMEM00 register. If an
LCD0BLINK bit corresponding to an LCD segment is set to 1, then that segment will toggle at the frequency set by
the LCD0TOGR register without any software intervention.
Address = 0x80
SFR Definition 12.8. LCD0BLINK: LCD0 Blink Mask
Bit76543210
Name LCD0BLINK[7:0]
Type R/WR/WR/WR/WR/WR/WR/WR/W
Reset 00000000
Bit Name Function
7:0 LCD0BLINK[7:0] LCD0 Blink Mask.
Each bit maps to a specific LCD segment connected to the LCD0 and L CD1 segment
pins. A value of 1 ind icates that the segment is blinking. A value of 0 indicates that the
segment is not blinking. This bit to segment mapping is the same as the ULPMEM00
register.
CP2400/1/2/3
92 Rev. 1.0
13. Timers
CP2400/1/2/3 devices include two 16-bit auto-reload timers. These timers can be used to measure time intervals
and generate periodic interrupt requests. Both timers can be clocked from the system clock source divided by 12.
Timer 1 has an additional SmaRTClock divided by 8 input and capture mode that can be used to measure the
SmaRTClock oscillation frequency with respect to the system clock. When SMBus SCL low timeout is enabled,
Timer 0 becomes unavailable for general purpose use. Timer 0 is enabled on reset.
13.1. Timer 0
Timer 0 is a 16-bit timer formed by two 8-bit SFRs: TMR0L (low byte) and TMR0H (high byte). Timer 0 operates in
16-bit auto-reload mode and is clocked by the system clock divided by 12. As the 16-bit timer register increments
and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 0 reload registers (TMR0RLH and TMR0RLL)
is loaded into the Timer 0 register as shown in Figure 13.1, and the Timer 0 Overflow Flag (INT1.2) is set. If
Timer 0 interrupts are enabled (if INT1EN.2 is set), an interrupt will be generated on each Timer 0 overflow.
Additionally, if Timer 0 interrupts are enabled and the TF0LEN bit is set (TMR0CN.5), an interrupt will be generated
each time the lower 8 bits (TMR0L) overflow from 0xFF to 0x00.
Figure 13.1. Timer 0 Block Diagram
SYSCLK / 12 TMR0L TMR0H
TMR0RLL TMR0RLH Reload
TR0
To SMBus
Low Byte
Overflow
T o In ter rup t
CP2400/1/2/3
Rev. 1.0 93
SFR Address = 0x54
SFR Definition 13.1. TMR0CN: Timer 0 Control
Bit76543210
Name TF0LEN TR0
Type R/WR/WR/WR/WR/WR/WR/WR/W
Reset 00000100
Bit Name Function
7:6 Unused Read = 00b. Write = Don’t Care.
5 TF0LEN Timer 0 Low Byte Interrupt Enable.
When set to 1, this bit enables Timer 0 Low Byte interrupts. If Timer 0 interrupts are enabled,
an interrupt will be generated when the low byte of Timer 0 overflows.
4:3 Unused Read = 00b. Write = Don’t Care.
2TR0Timer 0 Run Control.
Timer 0 is enabled by setting this bit to 1.
1:0 Unused Read = 00b. Write = Don’t Care.
CP2400/1/2/3
94 Rev. 1.0
SFR Address = 0x50
SFR Address = 0x51
SFR Definition 13.2. TMR0RLL: Timer 0 Reload Register Low Byte
Bit76543210
Name TMR0RLL[7:0]
Type R/W
Reset 10001101
Bit Name Function
7:0 TMR0RLL[7:0] Timer 0 Reload Register Low Byte.
TMR0RLL holds the low byte of the reload value for Timer 0.
SFR Definition 13.3. TMR0RLH: T imer 0 Reload Register High Byte
Bit76543210
Name TMR0RLH[7:0]
Type R/W
Reset 00110100
Bit Name Function
7:0 TMR0RLH[7:0] Timer 0 Reload Register High Byte.
TMR0RLH holds the high byte of the reload value for Timer 0.
CP2400/1/2/3
Rev. 1.0 95
SFR Address = 0x52
SFR Address = 0x53
SFR Definition 13.4. TMR0L: Timer 0 Low Byte
Bit76543210
Name TMR0L[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR0L[7:0] Timer 0 Low Byte.
Contains the low byte of the 16-bit Timer 0.
SFR Definition 13.5. TMR0H Timer 0 High Byte
Bit76543210
Name TMR0H[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR0H[7:0] Timer 0 High Byte.
Contains the hi gh byte of the 16-bit Timer 0.
CP2400/1/2/3
96 Rev. 1.0
13.2. Timer 1
Timer 1 is a 16-bit timer formed by two 8-bit SFRs: TMR1L (low byte) and TMR1H (high byte). Timer 1 operates in
16-bit auto-reload mode and is clocked by the system clock divided by 12 or SmaRTClock divided by 8. As the 16-
bit timer register increments and overflows from 0xFFFF to 0x0000, th e 16-bit value in the Timer 1 reload registers
(TMR1RLH and TMR1RLL) is loaded into the Timer 1 register as shown in Figure 13.1, and the Timer 1 Overflow
Flag (INT1.3) is set. If Timer 1 interrupts are enabled (if IN1EN.3 is set), an interrupt will be generated on each
Timer 1 overflow. Additionally, if T imer 1 interrupts are e nabled an d the T F0LEN bit is set (TMR0CN.5), an interru pt
will be generated each time the lower 8 bits (TMR0L) overflow from 0xFF to 0x00.
Figure 13.2. Timer 1 Block Diagram
SYSCLK / 12
Sma R TC lock / 8
TMR1L TMR1H
TMR1RLL TMR1RLH Reload
TR1
To CS0
Low By te
Overflow
To In te r ru p t
0
1
T1XCLK
CP2400/1/2/3
Rev. 1.0 97
13.2.1. Timer 1 SmaRTClock Oscillator Capture Mode
The Capture Mode in Timer 1 allows the SmaRTClock oscillator period to be measured against the system clock d
by 12. Setting TF1CEN to 1 enables the SmaRTClock Oscillator Capture Mode for Timer 1.
When Capture Mode is enabled, a capture event will be generated every 8 SmaRTClock oscillator cycles. When
the capture event occurs, the contents of Timer 1 (TMR1H:TMR1L) are loaded into the Timer 1 reload registers
(TMR3RLH:TMR3RLL) and the T1F interrupt flag is set (triggering an interrupt if Timer 1 interrupts are enabled).
By recording the difference between two successive timer capture values, the SmaRTClock period can be
determined with respect to the system clock divided by 12. The system clock divided by 12 should be much faster
than the SmaRTClock to achieve an accurate reading.
For example, if T1XCLK = 0b, and TF1CEN = 1b, Timer 1 will increment every 12 system clock cycles and capture
every 8 SmaRTClock cycles. If the system clock is 24.5 MHz and the SmaRTClock is 32.768 kHz, the difference
between two successive captur es should be approximately 498 counts. Knowing the system clock frequency, the
SmaRTClock frequency can be estimated as:
(SYSCLK x 8 / 12) / Counts = (24500000 Hz x 8 / 12) / 498 = 16333333 / 498 = 32797 Hz.
This mode allows software to determine the SmaRTClock oscillator frequency when the SmaRTClock oscillator is
being used in self-oscillate mode without a crystal.
Figure 13.3. Timer 1 Capture Mode Block Diagram
Sm aR T Clock / 8
SYSCLK / 12 TMR1L TMR1H
TCLK
TR1
TMR1RLL TMR1RLH
Capture
TF1CEN Interrupt
CP2400/1/2/3
98 Rev. 1.0
SFR Address = 0x59
SFR Definition 13.6. TMR1CN: Timer 1 Control
Bit76543210
Name TF1LEN TF1CEN TR1
Type R/W R/W R/W R/W R/W R/W R/W R/W
Reset 00000000
Bit Name Function
7:6 Unused Read = 00b. Write = Don’t Care.
5 TF1LEN Timer 1 Low Byte Interrupt Enable.
When set to 1, this bit enables Timer 1 Low Byte interrupts. If Timer 1 interrupt s are enabled,
an interrupt will be generated when the low byte of Timer 1 overflows.
4TF1CENTimer 1 SmaRTClock Oscillator Capture Enable.
When set to 1, this bit enables the Timer 1 SmaRTClock Oscillator capture mode.
3 Unused Read = 00b. Write = Don’t Care.
2TR1Timer 1 Run Control.
Timer 1 is enabled by setting this bit to 1.
1 Unused Read = 0b. Write = Don’t Care.
0T1XCLKTimer 1 External Clock Select.
0: Timer 1 is clocked from the system clock divided by 12.
1: Timer 1 is clocked from the SmaRTClock oscillator divided by 8.
CP2400/1/2/3
Rev. 1.0 99
SFR Address = 0x55
SFR Address = 0x56
SFR Definition 13.7. TMR1RLL: Timer 1 Reload Register Low Byte
Bit76543210
Name TMR1RLL[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR1RLL[7:0] Timer 1 Reload Register Low Byte.
TMR1RLL holds the low byte of the reload value for Timer 1.
SFR Definition 13.8. TMR1RLH: T imer 1 Reload Register High Byte
Bit76543210
Name TMR1RLH[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR1RLH[7:0] Timer 1 Reload Register High Byte.
TMR1RLH holds the high byte of the reload value for Timer 1.
CP2400/1/2/3
100 Rev. 1.0
SFR Address = 0x57
SFR Address = 0x58
SFR Definition 13.9. TMR1L: Timer 1 Low Byte
Bit76543210
Name TMR1L[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR1L[7:0] Timer 1 Low Byte.
Contains the low byte of the 16-bit Timer 1.
SFR Definition 13.10. TMR1H Timer 1 High Byte
Bit76543210
Name TMR1H[7:0]
Type R/W
Reset 00000000
Bit Name Function
7:0 TMR1H[7:0] Timer 1 High Byte.
Contains the hi gh byte of the 16-bit Timer 1.
CP2400/1/2/3
Rev. 1.0 101
14. Serial Peripheral Interface (SPI)
CP2400/2 devices have a 4-wire Serial Peripheral Interface which provides access to the internal registers and
memory. A typical connection to a SPI master is shown in Figure 14.1.
Figure 14.1. SPI Connection Diagram
14.1. Signal Descriptions
The four signals used by the SPI (MOSI, MISO, SCK, NSS) are described below.
14.1.1. Master Out, Slave In (MOSI)
The master- out, slave- in (MOSI) s ignal is a n output fr om a mas ter device and an inpu t to slave devices. It is used
to serially transf er data from the master to the slave. Th is signal is always in input for CP2402/1 devices. Data is
transferre d most-significant bit first.
14.1.2. Master In, Slave Out (MISO)
The master-in, slave-out (MISO) signal is an output from a slave device and an input to the master device. It is
used to serially transfer data from the slave to the master. This signal is always an output for CP2402/1 devices.
Data is transferred most-significant bit first. The MISO pin is placed in a high-impedance state when the slave
select (NSS) signal is de-asserted.
14.1.3. Serial Clock (SCK)
The serial clock (SCK) signal is an output from the master device and an input to slave devices. It is used to
synchronize the transfer of data between the master and slave on the MOSI and MISO lines. This signal is always
an input for CP2402/1 devices. The SCK signal is ignored when the slave select (NSS) signal is de-asserted.
14.1.4. Slave Select (NSS)
The active-low slave-select (NSS) signal allows support for multiple slave devices on a single bus. It is also used
by the CP2402/1 to detect the start and end of a SPI transfer.
Slave
Device
Master
Device MOSI
MISO
SCK
MISO
MOSI
SCK
NSS NSS
GPIO
Slave
Device
MOSI
MISO
SCK
NSS
INTGPIO
GPIO
INT
CP2400/1/2/3
102 Rev. 1.0
14.2. Serial Clock Timing
The clock to data relationship is shown in Figure 14.2. If the SPI master is a C8051 microcontroller, its SPI
peripheral must be configured for Mode 0 communication (CKPOL = 0, CKPHA = 0).
The maximum data transfer rate (bits/sec) for full-duplex operation is 1/10 the system clock frequency, provided
that the master issues SCK, NSS, and the serial input data synchronously with the system clock. If the master
issues SCK, NSS, and the serial inp ut dat a asynchronously, the maximum data transfe r rate (bit s/sec) must be less
than 1/10 the system clock frequency. In the special case where the master only wants to transmit data to the
device and does not need to receive data back (i.e. half-duplex operation), the slave can receive data at a
maximum data transfer rate (bits/sec) of 1/4 the system clock frequency. This is provided that the master issues
SCK, NSS, and the serial input data synchrono usly with the system clock.
Figure 14.2. Data/Clock Timing
M SB Bit 6 B it 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0MISO
NSS (4-Wire Mode)
M SB Bit 6 B it 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0MOSI
SCK
(CKPOL=0, CKPHA=0)
CP2400/1/2/3
Rev. 1.0 103
Figure 14.3. SPI Slave Timing
Table 14.1. SPI Slave Timing Parameters
Parameter Description Min Max Units
TSE NSS Falling to First SCK Edge 2 x TSYSCLK —ns
TSD Last SCK Edge to NSS Rising 2 x TSYSCLK —ns
TSEZ NSS Falling to MISO Valid — 4 x TSYSCLK ns
TSDZ NSS Rising to MISO High-Z — 4 x TSYSCLK ns
TCKH SCK High Time 5 x TSYSCLK —ns
TCKL SCK Low Time 5 x TSYSCLK —ns
TSIS MOSI Valid to SCK Sample Edge 2 x TSYSCLK —ns
TSIH SCK Sample Edge to MOSI Change 2 x TSYSCLK —ns
TSOH SCK Shift Edge to MISO Change — 4 x TSYSCLK ns
TSLH Last SCK Edge to MISO Change
(CKPHA = 1 ONLY) 6xT
SYSCLK 8xT
SYSCLK ns
Note: TSYSCLK is equal to one period of the device system clock (SYSCLK).
SCK*
TSE
NSS
TCKH
TCKL
MOSI
TSIS TSIH
MISO
TSD
TSOH
TSEZ T
SDZ
CP2400/1/2/3
104 Rev. 1.0
15. SMBus Interface
The SMBus I/O interface is a two-wire, bi-directional serial bus that can be used to access the internal registers
and memory on CP2401/3 devices. The SMBus is compliant with the System Management Bus Specification,
version 1.1, and compatible with the I2C serial bus. Reads and writes to the interface by the system cont roller are
byte oriented with the SMBus interface autonomously controlling the serial transfer of the data. Data can be
transferred at up to 1/20th of the system clock (this can be faster than allowed by the SMBus specification,
depending on the system clock used). A method of extending the clock-low du ration is available to accommodate
devices with different speed capabilities on the same bus.
15.1. Supporting Documents
It is assumed the reader is familiar with or has access to the following supporting documents:
1. The I2C-Bus and How to Use It (including specifications), Philips Semiconductor.
2. The I2C-Bus Specification—Version 2.0, Philips Semiconductor.
3. System Management Bus Specification—Version 1.1, SBS Implementers Forum.
15.2. SMBus Configuration
Figure 15.1 shows a typical SMBus configuration. The SMBus specification allows any recessive voltage between
3.0 V and 5.0 V; different devices on the bus may operate at different voltage levels. The bi-dir ectiona l SCL (serial
clock) and SDA (serial d ata) lines must be connected to a positive power supply voltag e through a pullup re sistor or
similar circuit. Every device connected to the bus must have an open-drain or open-collector output for both the
SCL and SDA lines, so that both are pulled high (recessive state) when the bus is free. The maximum number of
devices on the bus is limited only by the requirement that the rise and fall times on the bus not exceed 300 ns and
1000 ns, respectively.
Figure 15.1. Typical SMBus Configuration
VDD = 5 V
Master
Device Slave
Device 1 Slave
Device 2
VDD = 3 V VDD = 5 V VDD = 3 V
SDA
SCL
CP2400/1/2/3
Rev. 1.0 105
15.3. SMBus Operation
Two types of data transfers are possible: data transfers from a master transmitter to an addressed slave receiver
(WRITE), and data transfers from an addressed slave transmitter to a master receiver (READ). The master device
initiates both types of dat a tran sfers and provides the se rial clock pulses on SCL. The SMBus inter face on CP2401/
3 devices only supports slave receiver and slave transmitter modes.
A typical SMBus transaction consists of a START condition followed by an address byte (Bits7–1: 7-bit slave
address; Bit0: R/W direction bit), one or more bytes of data, and a STOP condition. Bytes that are received (by a
master or slave) are acknowledged (ACK) with a low SDA during a high SCL (see Figure 15.2). If the receiving
device does not ACK, the transmitting device will read a NACK (not acknowledge), which is a high SDA during a
high SCL.
The direction bit (R/W) occupies the least-significant bit position of the address byte. The dir ection bit is set to lo gic
1 to indicate a "READ" operation and cleared to logic 0 to indicate a "WRITE" operation.
All transactions are initiated by a master, with one or more addressed slave devices as the target. The master
generates the START condition and then transmits the slave address and direction bit. If the transaction is a
WRITE operation from the master to the slave, the master transmits the data a byte at a time waiting for an ACK
from the slave at the end of each byte. For READ operations, the slave transmits the data waiting for an ACK from
the master at the end of each byte. At the end of the data transfer, the master generates a STOP condition to
terminate the transaction and free the bus. Figure 15.2 illustrates a typical SMBus transaction.
Figure 15.2. SMBus Transaction
15.3.1. Transmitter Vs. Receiver
On the SMBus communications interface, a device is the “transmitter” wh en it is sending an address or dat a byte to
another device on the bus. A device is a “receiver” when an address or data byte is being sent to it from another
device on the bus. The transmitter controls the SDA line during the address or data byte. After each byte of
address or data information is sent by the transmitter, the receiver sends an ACK or NACK bit during the ACK
phase of the transfer, during which time the receiver controls the SDA line.
15.3.2. Clock Low Extension
SMBus provides a clock synchronization mechanism, similar to I2C, which allows devices with different speed
capabilities to coexist on the bus. A clock-low extension is used during a transfer in order to allow slower slave
devices to communicate with faster masters. The slave may temporarily hold the SCL line LOW to extend the clock
low period, effectively decreasing the serial clock frequency.
SLA6
SDA SLA5-0 R/W D7 D6-0
SCL
Slave Address + R/W Data ByteSTART ACK NACK STOP
CP2400/1/2/3
106 Rev. 1.0
15.3.3. SCL Low Timeout
If the SCL line is held low by a slave device on the bus, no further communication is possible. Furthermore, the
master cannot force the SCL line high to correct the error condition. To solve this problem, the SMBus protocol
specifies that devices participating in a transfer must detect any clock cycle held low longer than 25 ms as a
“timeout” condition. Devices that have detected the timeout condition must reset the communication no later than
10 ms after detecting the timeout condition.
When SMBus is used for communication with the host microcontroller, Timer 0 is used to detect SCL low timeout s.
Timer 0 is forced to reload when SCL is high, and allowed to count when SCL is low. With Timer 0 enabled and
configured to overflow after 25 ms, the Timer 0 interrupt service routine can be used to alert the host
microcontroller of an SCL Low Timeout. After an SCL Low Timeout, the SMBus slave will reset its internal state
machine and will be ready to respond to new transfers. On reset or wake-up from ULP mode, Timer 0 is enabled
and configured for SCL Low Timeout detection. The SCL Low Timeout may be disabled by clearing the SMBTOE
bit in the SMB0CF registe r. This allows full software control of Timer 0.
15.3.4. SCL High (SMBus Free) Timeout
The SMBus specification stipulates that if the SCL and SDA lines remain high for more that 50 µs, the bus is
designated as free. When the SMBFTE bit in SMB0CF is set, the bus will be considered free if SCL and SDA
remain high for more than 1250 system clock periods. After an SCL High Timeout, the SMBus slave will reset its
internal state machine and will be ready to respond to new transfers.
15.3.5. Slave Address Selection
CP2400/1/2/3 devices can have one of 2 possible 7-bit, left-justified slave addresses: 0x74 and 0x76. The least
significant bit of the slave address is set by the SMBA0 pin. The remaining bits in the slave address are fixed. The
bit following the least significant address bit is used to indicate whether the current transfer is a read or a write.
CP2400/1/2/3
Rev. 1.0 107
Address: 0x68
SFR Definition 15.1. SMBCF: SMBus Clock/Configuration
Bit 76543210
Name ENSMB INH BUSY EXTHOLD SMBTOE SMBFTE Reserved
Type R/W R/W R R/W R/W R/W R/W
Reset
(CP2400/2) 00000000
Reset
(CP2401/3) 10011100
Bit Name Function
7ENSMB
SMBus Enable.
This bit enables the SMBus interface when set to 1. When enabled, th e interface constantly
monitors the SDA and SCL pins.
6INH
SMBus Slave Inhibit.
When this bit is set to logic 1, the SMBus does not generate an interru pt when slave events
occur. This effectively removes the SMBus slave from the bus.
5BUSY
SMBus Busy Indicator.
This bit is set to logic 1 by hardware when a transfer is in progress. It is cleared to logic 0
when a STOP or free-timeout is sensed.
4 EXTHOLD
SMBus Setup and Hold Time Extension Enable.
This bit controls the SDA setup and hold times.
0: Setup time is 4 system clocks and hold time is 3 system clocks.
1: Setup time is 11 system clocks and hold time is 12 system clocks.
3SMBTOE
SMBus SCL Timeout Detection Enable.
This bit enables SCL low timeout detection. If set to logic 1, the SMBus forces Timer 0 to
reload while SCL is high and allows T imer 0 to count when SCL goes low. The T imer 0 reload
value should be set to overflow the timer after 25 ms.
2SMBFTE
SMBus Free T imeout Detection Enable.
When this bit is set to logic 1, the bus will be considered free if SCL and SDA remain high for
more than 50 µs.
1:0 Reserved Read = 00b. Must write 00b.
Note: This register has a reset value of 0x00 in devices that do not supp ort SMBus.
CP2400/1/2/3
108 Rev. 1.0
DOCUMENT CHANGE LIST
Revision 0.2 to Revision 1.0
Updated Electrical Specifications to remove TBDs and specify min/max parameters.
Updated Reset Values for various registers.
Updated Register Description for LCD0PWR register.
CP2400/1/2/3
Rev. 1.0 109
NOTES:
CP2400/1/2/3
110 Rev. 1.0
CONTACT INFORMATION
Silicon Laboratories Inc.
400 West Cesar Chavez
Austin, TX 78701
Please visit the Silicon Labs Techn i cal Support web page:
https://www.silabs.com/support/pages/contacttechnicalsupport.aspx
and register to submit a technical support request.
Silicon Laboratories, Silicon Labs, and USBXpress are trademarks of Silicon Laboratories Inc.
Intel, Motorola, and any other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders.
The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice.
Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from
the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed fea-
tures or parameters. Silicon Laboratories reserves the right to make changes without further notice. Silicon Laboratories makes no war-
ranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Silicon Laboratories assume
any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without
limitation consequential or incidental damages. Silicon Laboratories products are not designed, intended, or authorized for use in appli-
cations intended to support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create
a situation where personal injury or death may occur. Should Buyer purchase or use Silicon Laboratories products for any such unintended
or unauthorized application, Buyer shall indemnify and hold Silicon Laboratories harmless against all claims and damages.
