The DAC539G2-Q1
implements a cyclic redundancy check (CRC) feature for the NVM to
make sure that the data stored in the NVM is uncorrupted. There are
two types of CRC alarm bits implemented in DAC539G2-Q1:
- NVM-CRC-FAIL-USER
- NVM-CRC-FAIL-INT
The NVM-CRC-FAIL-USER bit indicates the status of the
user-programmable NVM bits, and the NVM-CRC-FAIL-INT bit indicates
the status of the internal NVM bits The CRC feature is implemented
by storing a 16-bit CRC (CRC-16-CCITT) along with the NVM data each
time an NVM program operation (write or reload) is performed and
during the device start-up. The device reads the NVM data and
validates the data with the stored CRC. The CRC alarm bits
(NVM-CRC-FAIL-USER and NVM-CRC-FAIL-INT in the GENERAL-STATUS
register) report any errors after the data are read from the device
NVM. The alarm bits are set only at boot up.