An SPI communication frame with the ADS130B04-Q1 is made of words. Words on DIN can contain commands, register settings during a register write, or a CRC of the input data. Words on DOUT can contain command responses, register settings during a register read, ADC conversion data, or CRC of the output data.

Words can be 16, 24, or 32 bits. The word size is configured by the WLENGTH[1:0] bits in the MODE register. The device defaults to a 24-bit word size. ADC conversion data, commands, responses, CRC, and registers always contain 16 bits of actual data. All words are most significant bit (MSB) aligned, and therefore the least significant bits (LSBs) are zero-padded to accommodate 24- or 32-bit word sizes.

Figure 8-14 through Figure 8-16 show the locations of the individual bits in an SPI frame for the different word size options using a WREG command frame for writing two registers as an example.