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

 

 

 

 

 

 

 

 

 

 

Bits

Access

Mnemonic

Reset

Description

 

 

 

 

 

D01:00

R/W

EXINT

0

External interface mode

 

 

 

 

00

MII normal operation, used for all MII-style

 

 

 

 

 

10/100 PHY devices

 

 

 

 

01

TP-PMD mode, used for PHYs that contain

 

 

 

 

 

their own non-standard PCS circuitry

 

 

 

 

10

10 Mbit mode, used for older

 

 

 

 

 

10-Mbit-only PHY devices that predate the

 

 

 

 

 

MII standard.

 

 

 

 

11

Reserved

 

 

 

 

 

 

Table 53: Ethernet General Control register bit definition

ENDEC mode and NS7520 pins

Table 54 shows the relationship between the lower bits in the Ethernet General Control register and the NS7520 pins that they control. The NS7520 pins are controlled by these bits only when the MODE field (D15:14) is set to ENDEC.

MODE field

Output based on EFE CSR bit

 

 

Not ‘b00

TXD1=PDN inverted, open drain

 

 

Not ‘b00

TXD2=AUI_TP[1]

 

 

Not ‘b00

TXD3=AUI_TP[0]

 

 

Not ‘b00

TXER=LNK_DIS_

 

 

Not ‘b00 and not ‘b11

MDC=LPBK

 

 

‘b11

MDC=LPBK inverted

 

 

Not ‘b00

MDO=UTP_STP

 

 

Table 54: ENDEC control signal cross-reference

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Image 177
Digi manual Endec mode and NS7520 pins, Endec control signal cross-reference, External interface mode