19.3.1 CRC from User Data
Data can be supplied to the CRC module by writing to the CRCDATA registers. Once data has been loaded into the CRCDATA registers, it will then be latched onto the CRC Shift (CRCSHIFT) registers. If data are still being shifted from an earlier write to the CRCDATA registers and the user attempts to write more data, the most recently written data will be held in the CRCDATA registers until the previous shift has completed.