Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.1.6.9.4. Reference Timing Source

The EMAC requires a reference time as defined in the IEEE 1588-2008 to get a snapshot of the time, It is configured to use to use internal reference time (80-bit) which allows takes only the reference PTP clock input to internally generate the Reference time and capture timestamps.

The EMAC supports the following reference timing source features:
  • Fixed pulse-per-second output - Supports the pulse-per-second (PPS) output which indicates 1 second interval by default. You can change the frequency of the PPS output by setting the PPSCTRL0 field in the MAC_PPS_Control register.
  • Flexible pulse-per-second output - Provides the flexibility to program the start or stop time, width, and interval of the pulse generated on the ptp_pps_o output.
  • Auxiliary snapshots with external events - Store a snapshot of the system time based on an external event. The event is considered to be the rising edge of the ptp_aux_ts_trig_i sideband signal. This feature is independent of whether the system time is generated internally or given as input on the ptp_timestamp_i[63:0] bus.