As described in Table 6, the host controller can use any of the four SPI protocols (SPI-00, SPI-01, SPI-10, or SPI-11) to write data into the device.
(At the CS Falling Edge)
|SDI_MODE[1:0] BITS(1)||SDO_MODE[1:0] BITS(2)||DIAGRAM|
On power-up or after coming out of any asynchronous reset, the device supports the SPI-00-S protocol for data read and data write operations. To select a different SPI-compatible protocol, program the SDI_MODE[1:0] bits in the SDI_CNTL register. This first write operation must adhere to the SPI-00-S protocol. Any subsequent data transfer frames must adhere to the newly-selected protocol. The SPI protocol selected by the SDI_MODE[1:0] configuration is applicable to both read and write operations.
As explained in the Register Read/Write Operation section, a valid register read or write operation to the device requires 24 SCLKs to be provided within a data transfer frame. When reading ADC conversion data, a minimum 16 SCLKs are required within a data transfer frame.