5.3.1 Accessing Indirect Registers

Pattern generation is access through the CSI-2 Pattern Generator and Timing Registers. Indirect registers hold many different registers—such as the CSI-2 Pattern Generation, Timing registers, and Analog controls—that are located at offsets of the main register space.

The indirect address mechanism involves setting the control register to select the desired block, setting the register offset address, and reading or writing the data register. In addition, an auto-increment function is provided in the control register to automatically increment the offset address following each read or write of the data register.

For writes, the process on both the 953 and the 954 is as follows:

1. Write to the IND_ACC_CTL register (0xB0) to select the desired register block.
2. Write to the IND_ACC_ADDR register (0xB1) to set the register offset.
3. Write the data value to the IND_ACC_DATA register (0xB2).

If auto-increment is set in the IND_ACC_CTL register, repeating step 3 will write additional data bytes to subsequent register offset locations.

For reads, the process on both the 953 and the 954 is as follows:

1. Write to the IND_ACC_CTL register (0xB0) to select the desired register block.
2. Write to the IND_ACC_ADDR register (0xB1) to set the register offset.
3. Read from the IND_ACC_DATA register (0xB2).

If auto-increment is set in the IND_ACC_CTL register, repeating step 3 will read additional data bytes from subsequent register offset locations.