SCPS125H April 2006 – March 2022 PCA9536
PRODUCTION DATA
Following the successful acknowledgment of the address byte, the bus controller sends a command byte that is stored in the control register in the PCA9536. Two bits of this data byte state the operation (read or write) and the internal register (Input, Output, Polarity Inversion, or Configuration) that will be affected. This register can be written or read through the I2C bus. The command byte is sent only during a write transmission.
Once a command byte has been sent, the addressed register is continuosly accessed by reads until a new command byte is sent.
Figure 8-7 shows the PCA9536 control register bits and Table 8-2 shows the command byte.
CONTROL REGISTER BITS | COMMAND BYTE (HEX) | REGISTER | PROTOCOL | POWER-UP DEFAULT | |
---|---|---|---|---|---|
B1 | B0 | ||||
0 | 0 | 0×00 | Input Port | Read byte | 1111 XXXX |
0 | 1 | 0×01 | Output Port | Read/write byte | 1111 1111 |
1 | 0 | 0×02 | Polarity Inversion | Read/write byte | 0000 0000 |
1 | 1 | 0×03 | Configuration | Read/write byte | 1111 1111 |