E-tile Hard IP User Guide: E-Tile Hard IP for Ethernet and E-Tile CPRI PHY Intel® FPGA IPs

ID 683468
Date 12/13/2021
Public

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2.9.2.2. PTP Timestamp Accuracy

The E-Tile Hard IP for Ethernet Intel® FPGA IP 10G/25G variants support two PTP accuracy modes, Basic Mode and Advanced Mode, selectable from the PTP Accuracy Mode drop down menu under PTP options.

The E-Tile Hard IP for Ethernet Intel® FPGA IP 100G variants support timestamping accuracy of +/-8ns.
Figure 21. 100G PTP Accuracy Block Diagram

PTP Timestamp Accuracy in Basic Mode

When you select Basic Mode in the PTP Accuracy Mode under PTP Options in the parameter editor, IP core requires a single TOD IP and a single TOD synchronizer IP. The TOD blocks are shared between 1 to 4 10G/25G Ethernet channels in the same IP core. Note that sharing TOD IP with different E-Tile Hard IP for Ethernet IP instances is not supported.

Figure 22. Basic Mode PTP Accuracy Block Diagram

PTP Timestamp Accuracy in Advanced Mode

When you select Advanced Mode in the PTP Accuracy Mode under PTP Options in the parameter editor, each channel in a 10G/25G Ethernet IP instance has two TOD interface ports, i_sl_ptp_tx_tod[95:0] (for TX port) and i_sl_ptp_rx_tod[95:0] (for RX port). Each channel in the same 10G/25G E-Tile Hard IP for Ethernet IP core requires two TOD IPs and two TOD Synchronizer IPs.

Figure 23. Advanced Mode PTP Accuracy Block Diagram

The functional usage of basic and advanced modes is the same. The advanced mode has additional clock inputs and TOD module requirements. Refer to the 10G/25G Ethernet Channel with Basic PTP Accuracy Mode for the clock connections and the External Time-Of-Day Module Variations with 1588 PTP Feature section for the TOD module connections in basic and advanced modes.

To improve accuracy, the advanced mode utilizes additional logic and TOD modules that affects the resource utilization. The advanced mode also requires an IOPLL and logic lock region requirements. For more information, refer to the Logic Lock Regions Requirements for PTP Accuracy Mode.

Table 22.  PTP Timestamp Accuracy per Ethernet Data Rate
Ethernet Data Rate PTP Timestamp Accuracy Parallel Clock Frequency
Basic Mode Advanced Mode
10GE ±3 ns ± 1.5 ns 402.83 MHz
25GE ±3 ns ± 1.5 ns 402.83 MHz
100GE ±8 ns N/A 402.83 MHz
Note: The 100G PAM4 configuration is not supported.