Ethernet Subsystem Registers
14.5.5.2 TX1_HDP Register (offset = A04h) [reset = 0h]
TX1_HDP is shown in
and described in
.
CPDMA_STATERAM TX CHANNEL 1 HEAD DESC POINTER *
Figure 14-90. TX1_HDP Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
TX_HDP
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 14-104. TX1_HDP Register Field Descriptions
Bit
Field
Type
Reset
Description
31-0
TX_HDP
R/W
0h
TX Channel (0..7) DMA Head Descriptor Pointer - Writing a TX DMA
Buffer Descriptor address to a head pointer location initiates TX
DMA operations in the queue for the selected channel.
Writing to these locations when they are non-zero is an error (except
at reset).
Host software must initialize these locations to zero on reset.
1325
SPRUH73H – October 2011 – Revised April 2013
Ethernet Subsystem
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