Digi NS7520 Invert the transmit clock input, PSOS pNA buffer descriptors, MAC software reset

Models: NS7520

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E F E c o n f i g u r a t i o n

Bits

Access

Mnemonic

Reset

Description

 

 

 

 

 

D11

R/W

TXCINV

0

Invert the transmit clock input

 

 

 

 

Set to 1 only when the external Ethernet PHY

 

 

 

 

generates a clock that is inverted in phase relative

 

 

 

 

to what the MAC is expecting.

 

 

 

 

This bit is not required for most commercially

 

 

 

 

available PHY devices.

 

 

 

 

 

D10

R/W

pNA

0

pSOS pNA buffer descriptors

 

 

 

 

0 Standard receiver format. The data block

 

 

 

 

immediately follows the 14-byte header block.

 

 

 

 

1 pSOS pNA receiver format. The receiver

 

 

 

 

inserts a 2-byte padding between the

 

 

 

 

14-byte header and the data block. This

 

 

 

 

configuration aligns both the header and the

 

 

 

 

data blocks on a 32-bit longword boundary.

 

 

 

 

 

D09

R/W

MAC_RESET

0

MAC software reset

 

 

 

 

0 Restore MAC to normal operation

 

 

 

 

1 Reset MAC host interface

 

 

 

 

 

D08

R/W

ITXA

0

Insert transmit source address

 

 

 

 

When set, forces the MAC to automatically insert

 

 

 

 

the Ethernet source MAC address into the Ethernet

 

 

 

 

transmit packet. The MAC address information is

 

 

 

 

provided by the data configured in the Station

 

 

 

 

Address registers (SA1, SA2, SA3).

 

 

 

 

When ITXA is cleared, the 7th through 12th bytes

 

 

 

 

in the Ethernet packet are ignored and replaced by

 

 

 

 

the size bytes in the MAC Address register.

 

 

 

 

 

D07:02

R/W

PDN:

0

ENDEC media control bits

 

 

AUI_TP:

 

Used only when the MODE field is configured for

 

 

LNK_DIS:

 

ENDEC mode. In this configuration, each register

 

 

LPBK:

 

bit is mapped to NS7520 pins, allowing the

 

 

UTP_STP

 

software to manipulate control signals on an

external ENDEC PHY device.

See Table 54 on page 163 for more information.

Table 53: Ethernet General Control register bit definition

1 6 2

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

Page 176
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Digi NS7520 Invert the transmit clock input, PSOS pNA buffer descriptors, MAC software reset, Endec media control bits