Datasheet

STTS751 SMBus interface
Doc ID 16483 Rev 5 11/36
3.2 WRITE byte
The WRITE byte protocol is used to write one byte of data to the registers as shown in
Tabl e 4. The gray data is sent by the STTS751 while the white data is sent by the host.
3.3 READ byte
The READ byte protocol is used to read one byte of data from the registers as shown in
Tabl e 5.
3.4 SEND byte
The SEND byte protocol is used to set the internal address register to the correct address. It
sends a register address with no data (see Tabl e 6). The SEND byte can be followed by the
RECEIVE byte protocol described below in order to read data from the register.
3.5 RECEIVE byte
The RECEIVE byte protocol is used to read data from the register when the internal register
address pointer is known (see Ta bl e 7). This can be used for consecutive reads of the same
register.
Table 4. SMBus WRITE byte protocol
Start Slave address WR ACK
Register
address
ACK Data ACK Stop
1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 8 bits 1 bit 1 bit
Table 5. SMBus READ byte protocol
Start Slave address WR ACK
Register
address
ACK Start Slave address RD ACK Data NACK Stop
1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit
Table 6. SMBus SEND byte protocol
Start Slave address WR ACK Register address ACK Stop
1 bit 7 bits 1 bit
1 bit 8 bits 1 bit 1 bit
Table 7. SMBus RECEIVE byte protocol
Start Slave address RD ACK Data NACK Stop
1 bit 7 bits 1 bit
1 bit 8 bits 1 bit 1 bit