Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 8/15/2024
Public
Document Table of Contents

17.6.5.2.4. Peer-to-Peer Transparent Clock

The peer-to-peer transparent clock differs from the end-to-end transparent clock in the way it corrects and handles the PTP timing messages. In all other aspects, it is identical to the end-to-end transparent clock.

In the peer-to-peer transparent clock, the computation of the link delay is based on an exchange of Pdelay_Req, Pdelay_Resp, and Pdelay_Resp_Follow_Up messages with the link peer. The residence time of the Pdelay_Req and the associated Pdelay_resp packets is added and inserted into the correction field of the associated Pdely_Resp_Followup packet.

Therefore, support for taking snapshot for the event messages related to Pdelay is added as shown in the table below.

Table 188.  Peer-to-Peer Transparent Clock: PTP Messages for Snapshot
PTP Messages
SYNC
Pdelay_Req
Pdelay_Resp

You can take the snapshot by setting the snapshot select bits (snaptypsel) to b'11 in the Timestamp Control register.