Low Latency 40- and 100-Gbps Ethernet MAC and PHY MegaCore Function User Guide

ID 683628
Date 12/28/2017
Public
Document Table of Contents

3.4.1.8. 1588 PTP Registers

The 1588 PTP registers together with the 1588 PTP signals process and provide Precision Time Protocol (PTP) timestamp information as defined in the IEEE 1588-2008 Precision Clock Synchronization Protocol for Networked Measurement and Control Systems Standard. The 1588 PTP module provides you the support to implement the 1588 Precision Time Protocol in your design.

Table 46.  TX 1588 PTP Registers

Addr

Name

Bit

Description

HW Reset Value

Access

0xA00 TXPTP_REVID [31:0] IP core revision ID. RO
0xA01 TXPTP_SCRATCH [31:0] Scratch register available for testing. 32'b0 RW
0xA02 TXPTP_NAME_0 [31:0] First 4 characters of IP core variation identifier string "40gPTPTxCSR" or "100gPTPTxCSR" RO
0xA03 TXPTP_NAME_1 [31:0] Next 4 characters of IP core variation identifier string "40gPTPTxCSR" or "100gPTPTxCSR" RO
0xA04 TXPTP_NAME_2 [31:0] Final 4 characters of IP core variation identifier string "40gPTPTxCSR" or "100gPTPTxCSR" RO
0xA05 TX_PTP_CLK_PERIOD [19:0] clk_txmac clock period.

Bits [19:16]: nanoseconds

Bits [15:0]: fraction of nanosecond

This value is set to the correct clock period for the required TX MAC clock frequency. The clock period is different for 40GbE variations and 100GbE variations. RW
0xA06–0xA09 Reserved [95:0] Reserved 96'b0 RO
0xA0A TX_PTP_EXTRA_LATENCY [31:0] User-defined extra latency the IP core adds to outgoing timestamps.

Bits [31:16]: nanoseconds

Bits [15:0]: fraction of nanosecond

32'b0 RW
0xA0B TX_PTP_ASYM_DELAY [18:0] Asymmetry adjustment as required for delay measurement. The IP core adds this value to the final delay. 19'b0 RW
0xA0C TX_PTP_PMA_LATENCY [31:0] Latency through the TX PMA. This is the delay from the TX MAC output to the tx_serial pin .

The IP core sets this register to a value that is sufficiently accurate in most cases. Altera recommends that you modify this value with extreme caution.

RW
Table 47.  RX 1588 PTP Registers

Addr

Name

Bit

Description

HW Reset Value

Access

0xB00 RXPTP_REVID [31:0] IP core revision ID. RO
0xB01 RXPTP_SCRATCH [31:0] Scratch register available for testing. 32'b0 RW
0xB02 RXPTP_NAME_0 [31:0] First 4 characters of IP core variation identifier string "40GPTPRxCSR" or "100GPTPRxCSR" RO
0xB03 RXPTP_NAME_1 [31:0] Next 4 characters of IP core variation identifier string "40GPTPRxCSR" or "100GPTPRxCSR" RO
0xB04 RXPTP_NAME_2 [31:0] Final 4 characters of IP core variation identifier string "40GPTPRxCSR" or "100GPTPRxCSR" RO
0xB05 RX_PTP_CLK_PERIOD [19:0] clk_rxmac clock period.

Bits [19:16]: nanoseconds

Bits [15:0]: fraction of nanosecond

This value is set to the correct clock period for the required RX MAC clock frequency. The clock period is different for 40GbE variations and 100GbE variations. RW
0xB06 RX_PTP_PMA_LATENCY [31:0] Latency through the RX PMA. This is the delay from the rx_serial pin to the RX MAC input.

The IP core sets this register to a value that is sufficiently accurate in most cases. Altera recommends that you modify this value with extreme caution.

RW