Datasheet

388
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
23. Cyclic Redundancy Check Calculation Unit (CRCCU)
23.1 Description
The Cyclic Redundancy Check Calculation Unit (CRCCU) has its own DMA which functions as a Master with the Bus
Matrix. Three different polynomials are available: CCITT802.3, CASTAGNOLI and CCITT16.
The CRCCU is designed to perform data integrity checks of off-/on-chip memories as a background task wthout CPU
intervention.
23.2 Embedded Characteristics
 Data Integrity Check of Off-/On-Chip Memories
 Background Task Without CPU Intervention
 Performs Cyclic Redundancy Check (CRC) Operation on Programmable Memory Area
 Programmable Bus Burden
Note: The CRCCU is designed to verify data integrity of off-/on-chip memories, thus the CRC must be generated and
verified by the CRCCU. The CRCCU performs the CRC from LSB to MSB. If the CRC has been performed with
the same polynomial by another device, a bit-reverse must be done on each byte before using the CRCCU.