w89c840af Winbond Electronics Corp America, w89c840af Datasheet - Page 70

• Manufacturer Part Number: w89c840af
• Description: 100/10mbps Ethernet Controller
• Manufacturer: Winbond Electronics Corp America

T01, Transmit Descriptor 1
The T01 is used to describe the Transmit Control for the current frame transmission
11
10
9
8
7
6:3
1
0
CSL
LC
TA
SQE
CC
TFU
DEF
NCS
Carrier Sense Lost:
When set, it indicates that there is a carrier sense lost during transmission. This
bit is valid only when TLD (T01[30]) is set, i.e when the current descriptor is the
last descriptor of the current frame.
This bit is not valid in internal loopback mode.
No Carrier Sense:
When set, it indicates that no carrier sense is presented during transmitting. This
bit is valid only when TLD (T01[30]) is set, i.e when the current descriptor is the
last descriptor of the current frame.
This bit is not valid in internal loopback mode.
Late Collision:
When set, it indicates that collision occurs after the 64 bytes collision window.
This bit is not valid if Transmit FIFO underflow bit(T00[1]) is set. This bit is
valid only when TLD (T01[30]) is set, i.e when the current descriptor is the last
descriptor of the current frame.
Transmit Aborted:
When set, it indicates that the transmission was aborted after 16 successive
collisions during the transmission. This bit is valid only when TLD (T01[30]) is
set, i.e when the current descriptor is the last descriptor of the current frame.
Signal Quality Error Status:
When set, it indicates that W89C840AF has detected a signal quality error signal
in a range of time after the frame was transmitted if the W879C840 is set in 10
Mbps mode. This bit is not valid if Transmit FIFO underflow bit (T00[1]) is set.
This bit is valid only when TLD (T01[30]) is set, i.e when the current descriptor
is the last descriptor of the current frame.
Collision Count:
The number of collisions occurred before the frame is transmitted. This bit is
valid only when TLD (T01[30]) is set, i.e when the current descriptor is the last
descriptor of the current frame.
Transmit FIFO Underflow.
This bit is set when the transmission process lacks data to transmit during frame
transmission. The transmit DMA state machine will enter in suspend state. This
bit is valid only when TLD (T01[30]) is set, i.e. when the current descriptor is
the last descriptor of the current frame.
Deferred:
When set, it indicates that the W89C840AF had to defer when ready to transmit
a frame because the carrier sense input was asserted before the W89C840AF gets
the grant to acquire the network media. This bit is valid only when TLD
(T01[30]) is set, i.e. when the current descriptor is the last descriptor of the
current frame.
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Publication Release Date:October 2000
Revision 1.01
W89C840AF