Visible to Intel only — GUID: ozv1537952087452
Ixiasoft
Visible to Intel only — GUID: ozv1537952087452
Ixiasoft
2.9.2.6. PTP Timestamp and TOD Formats
The E-Tile Hard IP for Ethernet Intel® FPGA IP supports a 96-bit timestamp (V2 format) or a 64-bit timestamp (correction-field format) in PTP packets.
The IP core completes all internal processing in the V2 format. However, if you specify V1 format for a particular PTP packet in one-step insertion mode, the IP core inserts the appropriate V1-format timestamp in the outgoing packet on the Ethernet link.
V2 Format
The IP core maintains the time-of-day (TOD) in V2 format according to the IEEE specification::
- Bits [95:48]: Seconds (48 bits).
- Bits [47:16]: Nanoseconds (32 bits). This field overflows at 1 billion.
- Bits [15:0]: Fractions of nanosecond (16 bits). This field is a true fraction; it overflows at 0xFFFF.
V1 Format
V1 timestamp format is specified in the IEEE specification:
- Bits [63:32]: Seconds (32 bits).
- Bits [31:0]: Nanoseconds (32 bits). This field overflows at 1 billion.
Correction Field Format
The Correction Field format is distinct from the V1 format. It is intended for use in transparent clock systems, in which each node adds its own residence time to a running total latency through the system. This format matches the format of the correction field in the packet, as used in transparent clock mode.
- Bits [63:16]: Nanoseconds (48 bits).
- Bits [15:0]: Fractions of nanosecond (16 bits). This field is a true fraction; it overflows at 0xFFFF.