19.1 Module Overview

The CRC module is coupled with a memory scanner that provides a means of performing CRC calculations in hardware, without CPU intervention. The memory scanner can automatically provide data from program Flash memory to the CRC module. The CRC module can also be operated by directly writing data to SFRs, without using a scanner.

The CRC module can be used to detect bit errors in the Flash memory using the built-in memory scanner or through user input RAM. The CRC module can accept up to a 32-bit polynomial with up to a 32-bit seed value. A CRC calculated check value (or checksum) will then be generated into the CRCOUT registers for user storage. The CRC module uses an XOR shift register implementation to perform the polynomial division required for the CRC calculation. This feature is useful for calculating CRC values of data being transmitted or received using communications peripherals such as the SPI, UART or I²C.