
CHAPTER 10
SERIAL INTERFACE FUNCTION
User’s Manual U12768EJ4V1UD
234
(1) IIC control register 0 (IICC0)
IICC0 is used to enable/disable I
2C operations, set wait timing, and set other I2C operations.
IICC0 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets IICC0 to 00H.
Caution
In I
2C bus mode, set the port 1 mode register (PM1) as follows. In addition, set each output latch to
0.
Set P10 (SDA) to output mode (PM10 = 0)
Set P12 (SCL) to output mode (PM12 = 0)
(1/4)
After reset: 00H
R/W
Address: FFFFF340H
7
6
5
4
3
2
1
0
IICC0
IICE
LREL
WREL
SPIE
WTIM
ACKE
STT
SPT
IICE
I
2C Operation Enable/Disable Specification
0
Operation Stopped. IIC status register 0 (IICS0) preset. Internal operation stopped.
1
Operation enabled.
Condition for clearing (IICE = 0)
Condition for setting (IICE = 1)
Cleared by instruction
When RESET is input
Set by instruction
LREL
Exit from Communications
0
Normal operation
1
This exits from the current communications operation and sets standby mode. This setting is automatically
cleared after being executed. Its uses include cases in which a locally irrelevant extension code has been
received.
The SCL and SDA lines are set to high impedance.
The following flags are cleared.
STD ACKD TRC COI EXC MSTS STT SPT
The standby mode following exit from communications remains in effect until the following communications entry conditions
are met.
After a stop condition is detected, restart is in master mode.
An address match or extension code reception occurs after the start condition.
Condition for clearing (LREL = 0)
Note
Condition for setting (LREL = 1)
Automatically cleared after execution
When RESET is input
Set by instruction
Note
This flag’s signal is invalid when IICE = 0.
Remark
STD:
Bit 1 of IIC status register 0 (IICS0)
ACKD: Bit 2 of IIC status register 0 (IICS0)
TRC:
Bit 3 of IIC status register 0 (IICS0)
COI:
Bit 4 of IIC status register 0 (IICS0)
EXC:
Bit 5 of IIC status register 0 (IICS0)
MSTS: Bit 7 of IIC status register 0 (IICS0)