Visible to Intel only — GUID: wfq1706171438721
Ixiasoft
Visible to Intel only — GUID: wfq1706171438721
Ixiasoft
4.7. Link Fault Signaling Interface
Local Fault (LF)
If an Ethernet PHY sublayer detects a fault that makes the link unreliable, it notifies the RS of the local fault condition. If unidirectional is not enabled, the core follows Clause 46. The RS stops sending MAC data, and continuously generates a remote fault status on the TX datapath. After a local fault is detected, the RX PCS modifies the MII data and control to send local fault sequence ordered sets. Refer to the Link Fault Signaling Based On Configuration and Status table.
The RX PCS cannot recognize the link fault under the following conditions:
- The RX PCS is not fully aligned.
- The bit error rate (BER) is high.
Remote Fault (RF)
If unidirectional is not enabled, the core follows Clause 46. If the RS receives a remote fault status, the TX datapath stops sending MAC data and continuously generates idle control characters. If the RS stops receiving fault status messages, it returns to normal operation, sending MAC client data. Refer to the Link Fault Signaling Based On Configuration and Status table below.
Link Status Signals
LINK_FAULT Register (0x405) | Real Time Link Status | Configured TX Behavior | Comment | |||||
---|---|---|---|---|---|---|---|---|
Bit [0] | Bit [3] | Bit [1] | Bit [2] | LF Received |
RF Received |
TX Data |
TX RF |
|
1'b0 | Don't care | Don't care | Don't care | Don’t care | Don’t care | On | Off | Disable Link fault signaling on TX. RX still reports link status. TX side Link fault signaling disabled on the link. TX data and idle. |
1'b1 | 1'b1 | Don't care | Don't care | Don't care | Don't care | Off | On | Force RF. TX: Stop data. Transmit RF only |
1'b1 | 1'b0 | 1'b1 | 1'b1 | Don't care | Don't care | On | Off | Unidir: Backwards compatible. TX: Transmit data and idle. No RF. |
1'b1 | 1'b0 | 1'b1 | 1'b0 | 1'b1 | 1'b0 | On | On | Unidir: LF received. TX: Transmit data 1 column IDLE after end of packet and RF |
1'b1 | 1'b0 | 1'b1 | 1'b0 | 1'b0 | 1'b1 | On | Off | Unidir: RF receives TX: Transmit data and idle. No RF. |
1'b1 | 1'b0 | 1'b1 | 1'b0 | 1'b0 | 1'b0 | On | Off | Unidir: No link fault TX: Transmit data and idle. No RF. |
1'b1 | 1'b0 | 1'b0 | Don't care | 1'b1 | 1'b0 | Off | On | Bidir: LF received TX: Stop data. Transmit RF only. |
1'b1 | 1'b0 | 1'b0 | Don't care | 1'b0 | 1'b1 | Off | Off | Bidir: RF received TX: Stop data. Idle only. No RF. |
1'b1 | 1'b0 | 1'b0 | Don’t care | 1'b0 | 1'b0 | On | Off | Bidir: No link fault TX: Transmit data and idle. No RF. |