Visible to Intel only — Ixiasoft
Visible to Intel only — Ixiasoft
1.2.3.1.7. Transmitter Gearbox
In addition to providing bus width adaptation, the transmitter gearbox provides the transmitter polarity inversion, bit reversal and bit-slip features.
Transmitter Bit Reversal
Transmitter Polarity Inversion
A high value on the tx_invpolarity register, which is accessed via the Avalon-MM PHY management interface, 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. Dynamically changing the tx_invpolarity register value 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.
If polarity inversion is asserted midway through a serializer word, the word will be corrupted.