11.2 ChipScope Pro IBERT - When using the TXOUTCLK for the system clock, changing the line rate of a channel effects the accuracy of BER calculations

AR#	33321	Search For Another Answer
Topic	SW-ChipScope IBERT
Last Updated	08/21/2009
Status	Active

Description

Keywords: GT, GTP, GTX, MGT, transceiver, TX, RX, Virtex-6, V6, virtex6

When using IBERT for Virtex-6, there is an option to use TXOUTCLK for the IBERT System Clock. When you use this option, changing the line rate of a channel in the ChipScope Analyzer effects the accuracy of BER calculations.

How do I work around this issue?

Solution

TXOUTCLK is the "reference clock" against which the line rates and clock frequencies are calculated. If the line rate of that channel is changed, the TXOUTCLK frequency changes, which effects all the other calculations in the Analyzer.

To work around this issue, do not change the line rate for that channel or generate multiple bitstreams with the different line rates you want. This issue will be resolved in ChipScope Pro IBERT 11.4.