Register write access is enabled by setting SPI_RD_EN = 0b. The 16-bit configuration registers are grouped in three register banks and are addressable with an 8-bit register address. Select register bank 1 and register bank 2 for read or write operation by configuring the PAGE_SEL0 and PAGE_SEL1 bits, respectively. Registers in bank 0 are always accessible, irrespective of the PAGE_SELx bits. These register addresses are unique and are therefore not used in register banks 1 and 2.

As shown in Figure 6-9, steps to write to a register are:

1. Frame 1: Write to register address 0x03 in register bank 0 to select either register bank 1 or bank 2 for a subsequent register write. This frame has no effect when writing to registers in bank 0.
2. Frame 2: Write to the register in the bank selected in frame 1. Repeat this step for writing to multiple registers in the same register bank.

Figure 6-9 Register Write