7.5.1.2 SPI Format

Figure 17. SPI Slave Mode Timing Diagram

The SPI input data (SDI) control word is 16 bits long and consists of the following format:

• 1 read or write bit W [15]
• 4 address bits A [14:11]
• 11 data bits D [10:0]

The SPI output data (SDO) word response word is 11 bits long (first 5 bits are don't cares). It contains the content of the register being accessed.

The MSB of the SDI word (W0) is the read/write bit. When W0 = 0, the input data is a write command. When W0 = 1, the input data is a read command.

For a write command: The response word is the data currently in the register being written.

For a read command: The response word is the data currently in the register being read.