5.1.1. Clocking PTP Timestamp Accuracy
The IP core supports two timestamps accuracy modes, Basic and Advanced. In advanced mode, additional logic generates the high accuracy PTP timestamps.
PTP Timestamp Accuracy in Basic Mode
When you select Basic in the Timestamp accuracy mode under PTP tab in the parameter editor for F-Tile Ethernet Multirate IP core, TX and RX data paths of multiple Ethernet IP instances share a single TOD clock output.
- The time-of-day (TOD) module can be shared across multiple IP instances of different data rates
- Any 390.625 MHz frequency clock source can drive the TOD clock
Figure 10. TOD Clock and TOD Connections in Basic Accuracy ModeThe figure displays recommended TOD clock connection. The TOD clock source should be 390.625 MHz.
PTP Timestamp Accuracy in Advanced Mode
When you select Advanced in the Timestamp accuracy mode under PTP tab in the parameter editor, the IP core requires a single Master TOD module and dedicated TOD Synchronizer and TOD modules for both, TX and RX PTP instances.
Figure 11. TOD Clock and TOD Connections in Advanced Accuracy ModeThe figure displays recommended TOD clock connection.
In your design, you can share the TX TOD across multiple instances. Follow these conditions when sharing TX TOD:
- TX transceiver reference clocks of each port are shared, or from the source with the same clock frequency PPM
- TX transceiver channel that output the clock driving the shared TOD must not reset after the TX div clock is stable
- While other ports are active, the IP does not allow dynamic reconfiguration to the port output that shared TX div clock. A dynamic reconfiguration of all ports together is allowed.
- All ports operate at the same Ethernet rate
Figure 12. TOD Clock Connections in Advanced Accuracy Mode: Sharing TX TOD
If you need to dynamically reconfigure your design to support 10G Ethernet with PTP, Intel® recommends the following TOD connection for PTP in Advanced accuracy mode. Single instance of TOD Synchronizer can only support a single synchronization mode and TOD module is needed for each rate in TX and RX PTP data path of each port. You must correctly configure the TOD multiplexer according to the current operating state.
Figure 13. TOD Clock Connections in Advanced Accuracy Mode for 10G Dynamic Reconfiguration
In your design, you can share TX TOD across multiple instances. Follow these conditions when sharing TX TOD:
- TX transceiver reference clocks of each port are shared, or from the source with the same clock frequency PPM
- TX transceiver channel that output the clock driving the shared TOD must not reset after the TX div clock is stable
- While other ports are active, the IP does not allow dynamic reconfiguration to the port output that shared TX div clock. A dynamic reconfiguration of all ports together is allowed.
- All ports operate at the same Ethernet rate
Figure 14. TOD Clock Connections in Advanced Accuracy Mode for 10G Dynamic Reconfiguration:Sharing TX TOD
The table below specifies the timestamp accuracy modes support per profile within each reconfiguration group. If you plan to use a secondary profile that does not support advanced accuracy mode, you must set the timestamp accuracy to Basic.
Reconfiguration Group | Base and Supported Secondary Profiles | Supported Timestamp Accuracy Mode |
---|---|---|
25GE-1 Reconfigurable | 1x 25GE-1 | Basic, Advanced |
1x 10GE-1 | Basic, Advanced | |
50GE-1 Reconfigurable | 1x 50GE-1 | Basic, Advanced |
1x 25GE-1 | Basic, Advanced | |
1x 10GE -1 | Basic, Advanced | |
100GE-4 Reconfigurable | 1x 100GE-4 | Basic, Advanced |
2x 50GE-2 | Basic, Advanced | |
1x 100GE-2 | Basic, Advanced | |
4x 25GE-1 | Basic, Advanced | |
4x 10GE-1 | Basic, Advanced | |
2x 50GE-1 | Basic | |
100GE-2 Reconfigurable | 1x 100GE-2 | Basic, Advanced |
2x 50GE-1 | Basic, Advanced | |
2x 25GE-1 | Basic, Advanced | |
2x 10GE-1 | Basic, Advanced | |
1x 50GE-2 | Basic | |
400GE-8 Reconfigurable | 1x 400GE-8 | Basic, Advanced |
2x 200GE-4 | Basic, Advanced | |
4x 100GE-2 | Basic, Advanced | |
200GE-4 Reconfigurable | 1x 200GE-4 | Basic, Advanced |
2x 100GE-2 | Basic, Advanced | |
1x 100GE-4 | Basic | |
2x 50GE-2 | Basic | |
4x 50GE-1 | Basic, Advanced |