NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 598 -
Revision V1.30
NUC97
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CHNIC
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TXDES 3: TXDMA Descriptor Word 3
The TXDMA descriptor word 3 contains the next TXDMA descriptor starting address or time
stamp most significant 32-bit value. The detail description of TXDES 3 is shown below.
31
30
29
28
27
26
25
24
NTXDSA/TSMSB
23
22
21
20
19
18
17
16
NTXDSA/TSMSB
15
14
13
12
11
10
9
8
NTXDSA/TSMSB
7
6
5
4
3
2
1
0
NTXDSA/TSMSB
Bits
Description
[31:0]
NTXDSA
Next TX Descriptor Starting Address
NTXDSA is the starting address of the next TX descriptor. When Ethernet MAC controller
fetch the next TX descriptor, it ignored the bits [1:0] of NTXDSA.
Bits
Description
[31:0]
TSMSB
Time Stamp Most Significant 32-bit
If TSEN (EMACn_TSCR[0]) and TTSEN of TX Descriptor word 0 are both enabled,
Ethernet MAC controller would store time stamp most signification 32-bit value, register
EMACn_TSMSR, into this field when it writes back TX Descriptor to system memory.