Xilinx, Inc.
Cyclic redundancy check engine and method therefor

Abstract:

An apparatus and method therefor relate generally to a CRC engine. In such a CRC engine, a feed forward circuit is coupled to a feedback circuit. The feed forward circuit includes: an offset circuit configured to determine an offset value from header data; a look-up table circuit configured to select a seed value responsive to the offset value; a shifter circuit configured to successively load a zero padding and a payload in multiple byte blocks as aligned data with the zero padding leading the payload for a non-zero value of the offset value in a first of the multiple byte blocks having the zero padding and a first portion of the payload; and a CRC circuit configured to receive data zeroes to a seed port thereof and the aligned data to a data port thereof to provide an interim CRC value.