E t h e r n e t M o d u l e

Bits

Access

Mnemonic

Reset

Description

 

 

 

 

 

D31

R/W

ERX

0

Enable receive FIFO

 

 

 

 

0 Disables inbound data flow and resets the FIFO

 

 

 

 

1 Enables inbound data flow

 

 

 

 

Set to 1 to allow data to be received from the MAC

 

 

 

 

receiver.

 

 

 

 

Set to 0 (clear) to reset the receive side FIFO.

 

 

 

 

 

D30

R/W

ERXDMA

0

Enable receive DMA

 

 

 

 

0 Disables inbound DMA data request

 

 

 

 

1 Enables inbound DMA data request

 

 

 

 

Set to 1 to allow the EFE module to issue receive

 

 

 

 

data move requests to the DMA controller.

 

 

 

 

Clear this bit to temporarily stall receive side

 

 

 

 

Ethernet DMA.

 

 

 

 

 

D29

R/W

ERXLNG

0

Accept long (>1520 bytes [MAXF setting])

 

 

 

 

receive packets

 

 

 

 

When set to 1, allows the MAC to accept packets

 

 

 

 

that are larger than 1520 bytes.

 

 

 

 

 

D28

R/W

ERXSHT

0

Accept short (<60 bytes) receive packets

 

 

 

 

When set to 1, allows the MAC to accept packets

 

 

 

 

that are smaller than 60 bytes.

 

 

 

 

The ERXSHT bit is used primarily for debugging.

 

 

 

 

 

D27

R/W

ERXREG

0

Enable Receive Data register ready interrupt

 

 

 

 

Set to 1 to generate an interrupt when data is

 

 

 

 

available in the RX FIFO.

 

 

 

 

 

D26

R/W

ERFIFOH

0

Enable receive data FIFO half full interrupt

 

 

 

 

Set to 1 to generate an interrupt when the RX FIFO

 

 

 

 

is at least half full (1024 bytes).

 

 

 

 

 

D25

R/W

ERXBR

0

Enable receive buffer ready interrupt

 

 

 

 

Set to 1 to generate an interrupt when a new data

 

 

 

 

packet is available in the RX FIFO.

Table 53: Ethernet General Control register bit definition

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Digi NS7520 manual Ethernet General Control register bit definition