Visible to Intel only — GUID: bmo1732556832183
Ixiasoft
Visible to Intel only — GUID: bmo1732556832183
Ixiasoft
2.1.1.8. F-Tile: Unsuccessful TX Equalization
Description
- For Gen3: Link Status 2 Register [4:1]:
- [1] Equalization 8.0 GT/s Complete
- [2] Equalization 8.0 GT/s Phase 1 Successful
- [3] Equalization 8.0 GT/s Phase 2 Successful
- [4] Equalization 8.0 GT/s Phase 3 Successful
- For Gen4: 16.0 GT/s Status Register [3:0]
- [0] Equalization 16.0 GT/s Complete
- [1] Equalization 16.0 GT/s Phase 1 Successful
- [2] Equalization 16.0 GT/s Phase 2 Successful
- [3] Equalization 16.0 GT/s Phase 3 Successful
If equalization is attempted, the “Complete” bit is set for that speed regardless if the other phases of equalization completed successfully. Once the “Complete” bit is set, the F-Tile permits a speed change by setting the Target Link Speed in the Link Control 2 Register. As a result, the link may train to Gen3/Gen4 speeds with sub-optimal transmitter equalization settings.
- For Gen3: Link Status 2 Register [4:1]
- For Gen4: 16.0 GT/s Status Register [3:0]
To re-initiate the equalization procedure, write 1b to the Perform Equalization bit [0] in the Link Control 3 register.
Workaround
- For Gen3: Both Equalization 8.0 GT/s Phase 3 Successful bit and Equalization 8.0 GT/s Complete bit of the Link Status 2 register are set to 1b.
- For Gen4: Both Equalization 16.0 GT/s Phase 3 Successful bit and Equalization 16.0 GT/s Complete bit of 16.0 GT/s Status Register are set to 1b.
- Writing 1b to the Perform Equalization bit in the Link Control 3 register.
- Followed by a write to the Target Link Speed field in the Link Control 2 register to enable the Link to run at 8.0 GT/s or higher.
- Followed by a write of 1b to the Retrain Link bit in the Link Control register of the Downstream Port.
Status
Devices Affected | Planned Fix |
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None |