Digi NS9750 User Manual

Page 370

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E t h e r n e t C o n t r o l a n d S t a t u s r e g i s t e r s

3 4 6

N S 9 7 5 0 H a r d w a r e R e f e r e n c e

D10

R

TXAEC

0x0

TX abort — excessive collisions

When set, indicates that the frame was aborted because
the number of collisions exceeded the value set in the
Collision Window/Retry register. If this bit is set, the

TX_WR

logic stops processing frames and sets the

TXERR bit in the Ethernet Interrupt Status register.

D09

R

TXAUR

0x0

TX abort — underrun

When set, indicates that the frame was aborted because
the TX_FIFO had an underrun. If this bit is set, the

TX_WR

logic stops processing frames and sets the

TXERR bit in the Ethernet Interrupt Status register.

D08

R

TXAJ

0x0

TX abort — jumbo

When set, indicates that the frame’s length exceeded the
value set in the Maximum Frame register (see
page 357). TXAJ is set only if the HUGE bit in MAC
Configuration Register #2 (see page 351) is set to 0.

Jumbo frames result in the TX buffer descriptor buffer
length field (see "Buffer length" on page 327) being set
to 0x000.

If the HUGE bit is set to 0, the frame is truncated. If
TXAJ is set, the

TX_WR

logic stops processing frames

and sets the TXERR bit in the Ethernet Interrupt Status
register.

D07

R

Not used

0x0

Always set to 0.

D06

R

TXDEF

0x0

Transmit frame deferred

When set, indicates that the frame was deferred for at
least one attempt, but less than the maximum number
for an excessive deferral. TXDEF is also set when a
frame was deferred due to a collision.

This bit is not set for late collisions.

D05

R

TXCRC

0x0

Transmit CRC error

When set, indicates that the attached CRC in the frame
did not match the internally-generated CRC. This bit is
not set if the MAC is inserting the CRC in the frame
(that is, the CRCEN bit is set in MAC Configuration
Register #2). If TXCRC is set, the

TX_WR

logic stops

processing frames and sets the TXERR bit in the
Ethernet Interrupt Status register.

Bits

Access

Mnemonic

Reset

Description

Table 209: Ethernet Transmit Status register

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