EMAC
Interrupts
DMA
Master
8k CPPI
RAM
EMAC
Module
Host CPU
Interface
DMA
Bus
MII/RMII
Bus
Interrupt
Combiner
C0
Interrupts
MDIO
Interrupts
MDIO
Module
Control Module
EMAC Sub System
MDIO
Bus
Introduction
1805
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
EMAC/MDIO Module
32.1.3 Functional Block Diagram
shows the three main functional modules of the EMAC/MDIO peripheral:
•
EMAC control module
•
EMAC module
•
MDIO module
The EMAC control module is the main interface between the device core processor to the EMAC and
MDIO modules. The EMAC control module controls device interrupts and incorporates an 8k-byte internal
RAM to hold EMAC buffer descriptors (also known as CPPI RAM).
The MDIO module implements the 802.3 serial management interface to interrogate and control up to 32
Ethernet PHYs connected to the device by using a shared two-wire bus. Host software uses the MDIO
module to configure the autonegotiation parameters of each PHY attached to the EMAC, retrieve the
negotiation results, and configure required parameters in the EMAC module for correct operation. The
module is designed to allow almost transparent operation of the MDIO interface, with very little
maintenance from the core processor.
The EMAC module provides an efficient interface between the processor and the network. The EMAC on
this device supports 10Base-T (10 Mbits/sec) and 100BaseTX (100 Mbits/sec), half-duplex and full-duplex
mode, and hardware flow control and quality-of-service (QOS) support.
shows the main interface between the EMAC control module and the CPU. The following
connections are made to the device core:
•
The DMA bus connection from the EMAC control module allows the EMAC module to read and write
both internal and external memory through the DMA memory transfer controller.
•
The EMAC control, EMAC, and MDIO modules all have control registers. These registers are memory-
mapped into device memory space. Along with these registers, the control module’s internal CPPI
RAM is mapped into this same range.
•
The EMAC and MDIO interrupts are combined into four interrupt signals within the control module. The
Vectored Interrupt Manager (VIM) receives all four interrupt signals from the combiner and submits
these interrupt requests to the CPU.
Figure 32-1. EMAC and MDIO Block Diagram