I2C Bus Controller
I2C Bus Interface Registers
Panasonic Semiconductor Development Company MN102H75K/F75K/85K/F85K LSI User Manual
304
Panasonic
13.7 I2C Bus Interface Registers
All registers in I2C blook cannot be written by byte (by word only). Read by byte
is possible.
I2CDTRM: I2C Transmission Data Register x’007E40’
SCL is held low during interrupt
servicing, and is cleared high by
a write to I2CDTRM.
STA: I2C start control
STO: I2C stop control
Writing to the STA and STO bits allows you to change the state of the
transmission or reception operation. Table 13-6 shows the settings for dif-
ferent start and stop conditions.
ACK: Acknowledge signal output control
The acknowledge signal is output after every byte transfer, on the ninth
clock pulse. ACK is normally 1 and transitions to 0 to output an acknowl-
edge (for instance if the master or slave receiver has received a data byte).
DT[7:0]: Data to be transmitted
The parallel data in this field is converted to serial data for transmission to
the I2C bus. It is shifted out MSB first to the interface.
Bit:1514131211109876543210
—————STASTOACKDT7DT6DT5DT4DT3DT2DT1DT0
Reset:0000000000000000
R/W:RRRRRR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/W
Table 13-6 STA and STO Settings
STA STO Mode Function Description
00All NOP No state change
11All NOP No state change
10Slave receiver Start Change to mode indicated by R/W bit.
R/W = 0: Change to master transmitter
R/W = 1: Change to master receiver
Master transmitter Repeat start
01Slave receiver Stop read Change to slave receiver after stop
condition.Master transmitter Stop write