AR# 34683: 11.x/12.x ChipScope, Virtex-6 - IBERT parameter sweep tests show errors in the middle of the eye
11.x/12.x ChipScope, Virtex-6 - IBERT parameter sweep tests show errors in the middle of the eye
The ChipScope Pro Serial I/O Tool Kit (also known as IBERT) has the ability to sweep through a variety of attribute settings for Virtex-6 FPGA GTs. When sweeping the data sample location through the eye, inexplicable errors might occur in what would be the middle of the data eye. There is an issue with IBERT 2.0 for the Virtex-6 FPGA sweep test. The sampling point is not moved during the test; therefore, whatever point the channel was using when the sweep test starts seems to be used regardless of the width of the eye sweep.
To work around this issue, set the sampling point by hand using the slider and observe the BER to determine the optimum value. This issue is scheduled to be resolved in a future release of the tools.