61.4.1.2 GMAC Features

  • GMAC0 supports RGMII, MII, RMII
  • GMAC1 supports MII, RMII
  • The media interface is configured using the GMAC_UR.MIM and GMAC_NCR.MII bits. Each interface has a dedicated clock configuration.
Important: The SAMA7G5 embeds two GMACs (GMAC0, GMAC1) with different configurations. This document describes GMAC0. The differences between GMAC0 and GMAC1 are listed below:
  • GMAC1 is 10/100 Mbps (no Gigabit support).
  • GMAC1 is MII/RMII (no RGMII support).
  • GMAC1 embeds 8 Kbytes of TX RAM (vs. 24 Kbytes) and 2 queues (vs. 6); the queue size remains unchanged.
  • GMAC1 does not support Credit-Based Shaping.
The information in this document on these characteristics is not applicable to GMAC1. Reading and writing corresponding registers and bits have no effect in the GMAC1 user interface.