SBAS590E March 2016 – June 2020 ADS131A02 , ADS131A04
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The CRC is calculated using specific device words in the data frame determined by the CRC_MODE bit in the D_SYS_CFG register. When the CRC_MODE = 1, the CRC is calculated using all of the bits sent to the device preceding the CRC word. For DIN this includes any command word, device words, and any zero words sent to the devices. For DOUT, all device words sent are used for the CRC. This includes the response word, device words, and ADC data words. However, when Hamming codes are enabled, the Hamming byte of each word is not used in the CRC calculation.
Figure 57 shows the device words used for calculating the CRC when the CRC_MODE is set to 1.
In addition to the CRC_MODE bit, the FIXED bit in the D_SYS_CFG register determines the number of words in the communication frame. When the FIXED bit is 1, the ADS131A04 has six device words per frame and the ADS131A02 has four device words per frame. When the FIXED bit is 0, each disabled ADC reduces the number of device words in the communication frame by 1.