tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 281

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

RA001
18.4 Functions
I
Serial bus interface data buffer register
18.4.1 Low Power Consumption Function
2
C bus address register
SBI0DBR
(0x0024)
(0x0025)
I2C0AR
Note 1: Don't set I2C0AR<SA> to "0x00". If it is set to "0x00", the slave address is deemed to be matched when the I
Note 2: Don't change the contents of the registers when the start condition is generated, the stop condition is generated or the
Note 3: After a software reset is generated, all the bits of the SBI0CR2 register except SBI0CR2<SBIM> and the SBI0CR1,
Note 4: When the operation is switched to STOP, IDLE0 or SLOW mode, the SBI0CR2 register, except SBI0CR2<SBIM>, and the
Note 1: Write the transmit data beginning with the most significant bit (bit 7).
Note 2: SBI0DBR has individual writing and reading buffers, and written data cannot be read out. Therefore, SBI0DBR must not
Note 3: Don't change the contents of the registers when the start condition is generated, the stop condition is generated or the
Note 4: To set SBI0CR2<PIN> to "1" by writing the dummy data to SBI0DBR, write 0x00. Writing any data other than 0x00 causes
Note 5: When the operation is switched to STOP, IDLE0 or SLOW mode, the SBI0CR2 register, except SBI0CR2<SBIM>, and the
bus interface is not being used.
Note that this makes the serial bus interface unusable. Setting POFFCR1<SBI0EN> to "1" enables the basic
clock supply to the serial bus interface and makes external interrupts usable.
using the serial bus interface for the first time, be sure to set POFFCR1<SBI0EN> to "1" in the initial setting of
the program (before the serial bus interface control registers are operated).
interface may operate unexpectedly.
The serial bus interface has a low power consumption register (POFFCR1) that saves power when the serial
Setting POFFCR1<SBI0EN> to "0" disables the basic clock supply to the serial bus interface to save power.
After reset, POFFCR1<SBI0EN> is initialized to "0", and this makes the serial bus interface unusable. When
Do not change POFFCR1<SBI0EN> to "0" during the serial bus interface operation, otherwise serial bus
dard start byte ("0x01") is received in the slave mode.
data transfer is in progress. Write data to the registers before the start condition is generated or during the period from
when an interrupt request is generated for stopping the data transfer until it is released.
I2C0AR and SBI0SR2 registers are initialized.
SBI0CR1, I2C0AR and SBI0DBR registers are initialized.
be accessed by using a read-modify-write instruction, such as a bit operation.
data transfer is in progress. Write data to the registers before the start condition is generated or during the period from
when an interrupt request is generated for stopping the data transfer until it is released.
an improper value in the subsequently received data.
SBI0CR1, I2C0AR and SBI0DBR registers are initialized.
Read/Write
Read/Write
Bit Symbol
Bit Symbol
After reset
After reset
ALS
SA
Slave address setting
Communication format selection
R/W
7
0
7
0
R/W
6
0
6
0
R/W
5
0
5
0
Page 267
0: I
1: Free data format
2
% bus mode
SA0
R/W
4
0
4
0
Slave address in the slave mode
SBI0DBR
R/W
R/W
3
0
3
0
R/W
2
0
2
0
R/W
1
1
0
0
TMP89FM42
2
ALS
R/W
C bus stan-
0
0
0
0