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Peripheral Architecture

2.8EMAC Module

This section discusses the architecture and basic function of the EMAC module.

2.8.1EMAC Module Components

The EMAC module (Figure 10) interfaces to the outside world through the Media Independent Interface (MII) and interfaces to the system core through the EMAC control module. The EMAC consists of the following logical components:

The receive path includes: receive DMA engine, receive FIFO, and MAC receiver

The transmit path includes: transmit DMA engine, transmit FIFO, and MAC transmitter

Statistics logic

State RAM

Interrupt controller

Control registers and logic

Clock and reset logic

Figure 10. EMAC Module Block Diagram

 

Clock and

 

Receive

 

 

Configuration bus

 

address

 

 

reset logic

 

 

 

 

 

 

 

 

 

 

 

 

 

Receive

Receive

MAC

 

 

 

DMA engine

FIFO

receiver

 

 

EMAC

Interrupt

State

 

 

MII

control

Statistics

SYNC

controller

RAM

module

 

 

 

 

 

 

 

 

 

Transmit

Transmit

MAC

 

 

 

DMA engine

FIFO

transmitter

 

 

Configuration bus

Control

 

 

 

 

registers

 

 

 

 

 

 

 

 

 

2.8.1.1Receive DMA Engine

The receive DMA engine is the interface between the receive FIFO and the system core. It interfaces to the CPU through the bus arbiter in the EMAC control module. This DMA engine is totally independent of the device DMA.

2.8.1.2Receive FIFO

The receive FIFO consists of three cells of 64-bytes each and associated control logic. The FIFO buffers receive data in preparation for writing into packet buffers in device memory.

2.8.1.3MAC Receiver

The MAC receiver detects and processes incoming network frames, de-frames them, and puts them into the receive FIFO. The MAC receiver also detects errors and passes statistics to the statistics RAM.

SPRU941A –April 2007Ethernet Media Access Controller (EMAC)/ 33

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Management Data Input/Output (MDIO)

 

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Texas Instruments TMS320DM643X DMP manual Emac Module Components, Receive DMA Engine, Receive Fifo, MAC Receiver