Visible to Intel only — GUID: nik1409855239941
Ixiasoft
Visible to Intel only — GUID: nik1409855239941
Ixiasoft
1.2.1.1.1. Transmitter Polarity Inversion
The positive and negative signals of a serial differential link might accidentally be swapped during board layout. The transmitter polarity inversion feature is provided to correct this situation without requiring a board re-spin or major updates to the logic in the FPGA fabric.
A high value on the tx_invpolarity port inverts the polarity of every bit of the input data word to the serializer in the transmitter datapath. Because inverting the polarity of each bit has the same effect as swapping the positive and negative signals of the differential link, correct data is sent to the receiver. The dynamic tx_invpolarity signal might cause initial disparity errors at the receiver of an 8B/10B encoded link. The downstream system must be able to tolerate these disparity errors.