E t h e r n e t f r o n t - e n d ( E F E )

Ethernet front-end (EFE)

Figure 21 shows a high-level block diagram of the EFE module. The EFE module provides the FIFO handling interface between the NS7520 BBus and MAC modules.

MAC RX interface

MAC TX interface

512 byte local Transmit

FIFO

RX

filtering & statistics

2K

byte

Local

Receive

FIFO

BBus

Figure 21: Ethernet front-end module

Basic features in the EFE include:

Control and status registers for MAC, transmitter, and receiver 512-byte transmit FIFO

2048-byte local receive FIFO DMA interface logic

1 5 0

N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v . D 0 3 / 2 0 0 6

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Image 164
Digi NS7520 manual Ethernet front-end EFE, Fifo