Visible to Intel only — GUID: nvr1673393543520
Ixiasoft
Visible to Intel only — GUID: nvr1673393543520
Ixiasoft
5.1.6.9.6. Transmit Path Functions
The EMAC captures a timestamp when the start packet delimiter (SFD) of a packet is sent on the GMII interface. The packets, for which you want to capture timestamps, can be controlled on per-packet basis. Each transmit packet can be marked to indicate whether a timestamp must be captured for it. The MAC does not process the transmitted packets to identify the PTP packets. You must specify the packets for which you want to capture timestamps.
TX Timestamp Status FIFO with Packet Identifier
The MAC provides option to store 16 captured timestamps with associated packet identifier provided by the application. These can be accessed through MAC_TxTimestamp_Status_PktID, MAC_TxTimestamp_Status_Seconds, and MAC_TxTimestamp_Status_Nanoseconds registers. The packet identifier helps the application to correlate the timestamp with the packet.
TTSE | OSTC | OSTPA | ATI Control Word 1 (TTSL and TTSH) | Timestamp Captured and Given in TS Status FIFO | Comments |
---|---|---|---|---|---|
0 | 0 | X | Not Valid | No | Default non-PTP packet |
0 | 1 | 0 | Not Valid | No | 1-step PTP packet to insert origin TS only (for example, SYNC, DelayResp. PdelayResp) |
0 | 1 | 1 | Ingress TS | No | 1-step PTP packet for either inserting origin timestamp, updating correction, or both. |
1 | 0 | 0 | Not Valid | Yes (PID = 0) | PTP 2-step without PID (for example, any PTP event message) |
1 | 1 | 0 | Not Valid | Yes (PID = 0) | 1-step PTP packet to insert origin TS (Example: SYNC, DelayResp. PdelayResp) |
1 | 0 | 1 | Packet ID | Yes with PID | PTP 2-step with PID (Example: Any PTP event message) |
1 | 1 | 1 | Ingress TS | Yes (PID = 0) | 1-step PTP packet to insert origin TS, update correction and also give origin TS to software (DelayReq, PDelayReq) |