Chapter 8: Cyclic Redundancy Check (Crc); Overview - Xilinx Virtex-5 RocketIO GTP User Manual

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Cyclic Redundancy Check (CRC)

Overview

In Virtex-5 devices, each high-speed transceiver tile is paired with two CRC integrated
blocks. Each CRC block can operate independently as two 32-bit input CRC modules
(CRC32) or can be combined into a single 64-bit input CRC module (CRC64). The CRC
modules use the standard 32-bit Ethernet polynomial for CRC calculation. The CRC
integrated blocks are independent of the transceiver blocks.
Figure 8-1
For clarification:
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Figure 8-2
Virtex-5 RocketIO GTP Transceiver User Guide
UG196 (v1.3) May 25, 2007
shows the basic port interface of the CRC block.
CRCIN[63/31:0]
CRCDATAVALID
CRCDATAWIDTH[2:0]
CRCRESET
CRCCLK
Figure 8-1: CRC Integrated Block
Each GTP_DUAL tile is paired with two integrated CRC blocks.
Each integrated CRC block can either operate as one 64-bit wide CRC module or as
two independent 32-bit wide CRC modules.
For a given GTP_DUAL, four independent 32-bit wide CRC modules are only
possible when a 64-bit wide CRC module is not used.
shows how CRC modules are typically used in an application.
www.xilinx.com
CRC Block
Chapter 8
CRCOUT[31:0]
UG196_c8_01_100506
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