Stratix V Device Handbook: Volume 2: Transceivers

ID 683779
Date 11/23/2021
Document Table of Contents Receiver Gearbox

The PMA bus width is smaller than the physical coding sublayer (PCS) bus width; therefore, the receiver gearbox expands the data bus width from the PMA to the PCS. Because bus width adaptation is transparent, you can continuously feed data to the receiver gearbox. In addition to providing bus width adaptation, the receiver gearbox provides the receiver polarity inversion and receiver bit reversal features.

Receiver Polarity Inversion

The receiver gearbox can invert the polarity of the incoming data. This is useful if the receive signals are reversed on the board or backplane layout.

Receiver Bit Reversal

The receiver gearbox allows bit reversal of the received data. Some protocols, such as Interlaken, require the bit reversal feature.