SBAS868A May 2019 – May 2020 ADS7128
PRODUCTION DATA.
The ADS7128 features a cyclic redundancy check (CRC) module for checking the integrity of the data bits exchanged over the I2C interface. The CRC module is bidirectional and appends an 8-bit CRC to every byte read from the device while also evaluating the CRC of every incoming byte over the I2C interface. The CRC module uses the CRC-8-CCITT polynomial (x8 + x2 + x + 1) for CRC computation.
To enable the CRC module, set the CRC_EN bit in the GENERAL_CFG register. Table 6 shows how a CRC error can be detected when configuring the ADS7128.
CRC ERROR NOTIFICATION | CONFIGURATION | DESCRIPTION |
---|---|---|
ALERT pin | ALERT_CRCIN = 1b | ALERT pin is asserted if a CRC error is detected by the device. |
Status flags | APPEND_STATUS = 10b | 4-bit status flags are appended to the ADC data; see the Output Data Format section for details. |
Register read | — | Read the CRC_ERR_IN bit to check if a CRC error is detected. |
When the ADS7128 detects a CRC error, the erroneous data are ignored and the CRC_ERR_IN bit is set. Table 6 describes the additional notifications that can be enabled. Further register writes are disabled until the CRC_ERR_IN bit is cleared by writing 1b to it. When using autonomous mode, further conversions can be disabled on the CRC error by setting CONV_ON_ERR to 1b; see the Autonomous Mode section.