PHY Status/Control Register (Offset 0x144) - 3.0 English

AXI Bridge for PCI Express Gen3 Subsystem Product Guide (PG194)

Document ID
PG194
Release Date
2023-11-24
Version
3.0 English

The PHY Status/Control register (described in the following table) provides the status of the current PHY state, as well as control of speed and rate switching for Gen2-capable cores.

Table 1. PHY Status/Control Register
Bits Name Core Access Reset Value Description
0 Link Rate is Gen2 RO 0 Reports the current link rate.

0b = 2.5 GT/s (if bit[12] = 0), or 8.0GT/s (if bit[12] = 1)

1b = 5.0 GT/s

2:1 Link Width RO 0 Reports the current link width.

00b = x1

01b = x2

10b = x4

11b = x8

8:3 LTSSM State RO 0 Reports the current Link Training and Status State Machine (LTSSM) state. Encoding is specific to the underlying integrated block.
10:9 Reserved RO 0 Reserved
11 Link Up RO 0 Reports the current PHY Link-up state.

1b: Link up

0b: Link down

Link up indicates the core has achieved link up status, meaning the LTSSM is in the L0 state and the core can send/receive data packets.

12 Link Rate is Gen3 RO 0 Reports the current link rate.

0b = see bit[0]

1b = 8.0 GT/s

13 Link Width is x16 RO 0 Reports the current link width.

0b = See bit[2:1]

1b = x16

31:13 Reserved RO 0 Reserved