PCI Express* Receiver Lane Polarity Inversion

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The PCI Express* Base Specification requires polarity inversion to be supported independently by all receivers across a Link where each differential pair within each Lane of a PCIe* Link handles its own polarity inversion. Polarity inversion is applied, as needed, during the initial training sequence of a Lane. In other words, a Lane will still function correctly even if a positive (Tx+) signal from a transmitter is connected to the negative (Rx-) signal of the receiver. Polarity inversion eliminates the need to untangle a trace route to reverse a signal polarity difference within a differential pair and no special configuration settings are necessary in the PCIe* Controllers to enable it.

Note:The polarity inversion does not imply direction inversion or direction reversal; that is, the Tx differential pair from one device must still connect to the Rx differential pair on the receiving device, per the PCIe* Base Specification. Polarity Inversion is not the same as “PCI Express* Controller Lane Reversal”.

Precision Time Measurement (PTM)

Single - Root I/O Virtualization (SR - IOV) Precision Time Measurement (PTM)