I/O Interfaces

Versal ACAP Technical Reference Manual (AM011)

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1.5 English

The controller provides I/O signals for two I/O interface paths:

  • GMII/MII to the EMIO PL interface
  • RGMII to the LPD MIO pins

GMII/MII Interface

The controller natively includes a GMII/MII interface that is routed to the EMIO PL interface where it can be converted to another format or consumed as is. The interface is also routed to the built-in RGMII adapter.

RGMII Interface

The controller includes a GMII to RGMII adapter. The RGMII I/O interface is multiplexed through the LPD MIO for connection to an external PHY. This interface supports the 10/100/1000 Mb/s protocol. See the MIO - RGMII Interface Signals section.

MDIO to External PHY for RGMII

To support the external PHY for the RGMII interface, the controller includes a management data input/output (MDIO) interface. The MDIO interface includes clock, data, and output enable signals that are routed from the controller to LPD MIO pins. See MDIO Interface Signals section.

Internal Loopback

The controller has an internal loopback from the TXD to RXD signals in the GMII/MII controller.

  • Ethernet loopback connecting TXD to RXD within a controller using the Network_Control [loopback_local] regoster bit.

In MAC internal loopback mode, both transmit and receive clock are sourced from the GEM_REF_CLK from the LPD clock controller.

Important: Receive and transmit must be disabled when making the switch into and out of internal loopback because the clocks provided might glitch while switching to the loopback reference clock.