Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 10/10/2025
Public
Document Table of Contents

12.3.2. GMII to SGMII+ through Multirate Ethernet PHY Adapter via FPGA Transceiver

To support the 2.5G rate, you must enable the 8-bit GMII interface to FPGA fabric. From there, it connects to a different PHY device via the FPGA transceivers, which then drives the copper media.

This configuration enables the data path between HPS, XGMAC, multirate PHY (Direct mode), and the PHY operating at 2.5G rate. The multirate PHY IP supports SGMII+ interface, which can work on the 10M/100M/1G/2.5G data rates. The SGMII interface supports only 10M/100M/1G data rates.

Table 353.  Multirate Ethernet PHY Use Case
Multirate Ethernet PHY Use Case 1G Support 2.5G Support
10M/100M/1G bps

Yes

1G 41, non-PTP

No
1G static

Yes

1G41

No
2.5G static No Yes
1G/2.5G dynamic reconfiguration

Yes

1G41

Yes
Note: 10M/100M does not support precision time protocol (PTP).
Figure 309.  Multirate Ethernet PHY Time Sensitive Network (TSN) Design Block Diagram

Dynamic Reconfiguration

You can change the PHY speed using the dynamic reconfiguration (DR) controller block in the Multirate Ethernet PHY system example design. To enable DR for multiple transceiver channels (one Multirate Ethernet PHY IP for each channel), you must generate the Multirate Ethernet PHY IP with the required settings and supported number of profiles.

Figure 310. DR Enablement for Multiple Transceiver Channels