9.5.3 I2C Control Behavior
Follow this procedure to write to the SNx5DP149 device I2C registers:
- The master initiates a write operation by generating a start condition (S), followed by the SNx5DP149 device 7-bit address and a zero-value W/R bit to indicate a write cycle.
- The SNx5DP149 device acknowledges the address cycle by combination of A0 and A1.
- The master presents the subaddress (I2C register within SNx5DP149 device) to be written, consisting of one byte of data, MSB-first.
- The SNx5DP149 device acknowledges the subaddress cycle.
- The master presents the first byte of data to be written to the I2C register.
- The SNx5DP149 device acknowledges the byte transfer.
- The master may continue presenting additional bytes of data to be written, with each byte transfer completing with an acknowledge from the SNx5DP149 .
- The master terminates the write operation by generating a stop condition (P).
Follow this procedure to read the SNx5DP149 I2C registers:
- The master initiates a write operation by generating a start condition (S), followed by the SNx5DP149 7-bit address and a zero-value W/R bit to indicate a write cycle.
- The SNx5DP149 device acknowledges the address cycle by combination of A0 and A1.
- The master presents the subaddress (I2C register within SNx5DP149 device) to be read, consisting of one byte of data, MSB-first.
- The SNx5DP149 device acknowledges the subaddress cycle.
- The master initiates a read operation by generating a start condition (S), followed by the SNx5DP149 7-bit address and a one-value W/R bit to indicate a read cycle.
- The SNx5DP149 device acknowledges the address cycle.
- The SSNx5DP149 device transmit the contents of the memory registers MSB-first starting at the written subaddress.
- The SNx5DP149 device will wait for either an acknowledge (ACK) or a not-acknowledge (NACK) from the master after each byte transfer; the I2C master acknowledges reception of each data byte transfer.
- If an ACK is received, the SNx5DP149 device transmits the next byte of data.
- The master terminates the read operation by generating a stop condition (P).
NOTE
No sub-addressing is included for the read procedure, and reads start at register offset 00h and continue byte by byte through the registers until the I2C master terminates the read operation.
Refer to Table 6 for the SNx5DP149 device local I2C register descriptions. Reads from reserved fields return 0s and writes are ignored.