Status flags can be appended to the ADC output by setting APPEND_STATUS = 10b. The status flag is appended only to frames where ADC data are being read. Status flags are not appended to data corresponding to a register read operation or when FIX_PAT = 1b. The 4-bit status flag field is constructed as follows:

Status flag[3:0] = { 1, VTEST_MODE, CRCERR_IN, DIAG_MODE }

where:

• VTEST_MODE: This flag is set if the current data frame corresponds to fixed voltage test mode (see the Fixed Voltage Test Mode section).
• CRCERR_IN: This flag indicates the status of the CRC verification of data received from the digital interface. This flag is the same as the CRCERR_IN bit in the SYSTEM_STATUS register.
• DIAG_MODE: This flag is set if the current data frame corresponds to the bit-walk test mode (see the Bit-Walk Test Mode section).