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Rainbow Electronics W90P710CDG User Manual

Page 107

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W90P710CD/W90P710CDG

Publication Release Date: September 19, 2006

- 107 -

Revision B2

TXINTR [16]: Transmit Interrupt
The TXINTR indicates the packet transmission caused an interrupt condition.
1’b0: The packet transmission doesn’t cause an interrupt.
1’b1: The packet transmission caused an interrupt.

TBC [15:0]: Transmit Byte Count
The TBC indicates the byte count of the frame stored in the data buffer pointed by Tx descriptor for
transmission.

Tx Descriptor Word 3

31

30

29

28

27

26

25

24

NTXDSA

23

22

21

20

19

18

17

16

NTXDSA

15

14

13

12

11

10

9

8

NTXDSA

7

6

5

4

3

2

1

0

NTXDSA

NTXDSA [31:0]: Next Tx Descriptor Starting Address
The Tx descriptor is a link-list data structure. Consequently, NTXDSA is used to keep the starting
address of the next Tx descriptor. The bits [1:0] will be ignored by EMC. So, all Tx descriptor must
locate at word boundary memory address.