Information

Chapter 31
Cyclic redundancy check (CRC)
31.1 Introduction
NOTE
For the chip-specific implementation details of this module's
instances see the chip configuration chapter.
The cyclic redundancy check (CRC) module generates 16/32-bit CRC code for error
detection.
The CRC module provides a programmable polynomial, WAS, and other parameters
required to implement a 16-bit or 32-bit CRC standard.
The 16/32-bit code is calculated for 32 bits of data at a time.
31.1.1 Features
Features of the CRC module include:
• Hardware CRC generator circuit using a 16-bit or 32-bit (programmable) shift
register.
• Programmable initial seed value and polynomial.
• Option to transpose input data or output data (the CRC result) bitwise or bytewise.
This option is required for certain CRC standards. A bytewise transpose operation is
not possible when accessing the CRC data register via 8-bit accesses. In this case, the
user's software must perform the bytewise transpose function.
• Option for inversion of final CRC result.
• 32-bit CPU register programming interface.
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc. 709