Register 53: Ethernet MAC Transmit Poll Demand (EMACTXPOLLD), offset
0xC04
The
MAC Transmit Poll Demand (EMACTXPOLLD)
register enables the TX DMA to check whether
or not the DMA owns the current descriptor. The Transmit Poll Demand command is given to wake
up the TX DMA if it is in the suspend mode. The TX DMA can go into the SUSPEND mode because
of an underflow error in a transmitted frame or the unavailability of descriptors owned by it. This
Transmit Poll Demand command can be given at any time and the TX DMA resets this command
when it again starts fetching the current descriptor from host memory.
Ethernet MAC Transmit Poll Demand (EMACTXPOLLD)
Base 0x400E.C000
Offset 0xC04
Type WO, reset 0x0000.0000
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
TPD
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
TPD
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
Description
Reset
Type
Name
Bit/Field
Transmit Poll Demand
When these bits are written with any value, the DMA reads the current
descriptor pointed to by the
MAC Current Host Transmit Descriptor
(EMACHOSTXDESC)
register. If that descriptor is not available (owned
by the Host), the transmission returns to the SUSPEND state and the
TU
bit of the
EMACDMARIS
is asserted. If the descriptor is available,
the transmission resumes.
0x0
WO
TPD
31:0
1557
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller