JAJSOO3B October 2014 – October 2024 TMP75B-Q1
PRODUCTION DATA
The device that initiates the transfer is called a controller, and the devices controlled by the controller are targets. The bus must be controlled by a controller device that generates the serial clock (SCL), controls the bus access, and generates the start and stop conditions.
To address a specific device, initiate a start condition by pulling the data line (SDA) from a high to a low logic level while SCL is high. All targets on the bus shift in the target address byte; the last bit indicates whether a read or write operation follows. During the ninth clock pulse, the target being addressed responds to the controller by generating an acknowledge bit and pulling SDA low.
Data transfer is then initiated and sent over eight clock pulses followed by an acknowledge bit. During data transfer, SDA must remain stable while SCL is high because any change in SDA while SCL is high is interpreted as a start or stop signal.
After all data have been transferred, the controller generates a stop condition indicated by pulling SDA from low to high, while SCL is high.