GD32F20x User Manual
815
Note
: When a frame is described by more than one descriptor, only the control bits of the first
descriptor are accept by TxDMA controller (except INTC). But the status and timestamp (if
enabled) are written back to the last descriptor.
Figure 27-9. Transmit descriptor
TDES0: Transmit descriptor word 0
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
DAV
INTC
LSG
FSG
DCRC
DPAD
TTSEN
Reserved
CM[1:0]
TERM
TCHM
Reserved
TTMSS
IPHE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ES
JT
FRMF
IPPE
LCA
NCA
LCO
ECO
VFRM
COCNT[3:0]
EXD
UFE
DB
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits
Fields
Descriptions
31
DAV
DAV bit
The DMA clears this bit either when it completes the frame transmission or the buffer
allocated in the descriptor is read completely. This bit of the frame’s first descriptor
must be set after all subsequent descriptors belonging to the same frame have been
set.
0: The descriptor is available for CPU not for DMA
1: The descriptor is available for DMA not for CPU
30
INTC
Interrupt on completion bit
This is valid only when the last segment (TDES0[29]) is set.
0: TS bit in ENET_DMA_STAT is not set when frame transmission complete.
1: TS bit in ENET_DMA_STAT is set when frame transmission complete.
29
LSG
Last segment bit
This bit indicates that the buffer contains the last segment of the frame.
0: The buffer of descriptor is not stored the last part of frame
1: The buffer of descriptor is stored the last part of frame
28
FSG
First segment bit
This bit indicates that the buffer contains the first segment of a frame.
0: The buffer of descriptor is not stored the first block of frame
1: The buffer of descriptor is stored the first block of frame
D
A
V
Buffer 2 address[31:0] or Next descriptor address[31:0]/Timestamp High[31:0]
Buffer 1 address[31:0]/Timestamp Low[31:0]
Buffer 1 byte size
[12:0]
Reserved
[31:29]
Buffer 2 byte size
[28:16]
T
T
S
E
N
R
e
s
Status[16:0]
T
T
M
S
S
Ctrl
[30:26]
Res
[19:
18]
Ctrl
[23:20]
Reserved
[15:13]
31
0
16
TDES0
TDES1
TDES2
TDES3
Содержание GD32F20 Series
Страница 1: ...GigaDevice Semiconductor Inc GD32F20x ARM Cortex M3 32 bit MCU User Manual Revision 2 2 Oct 2019 ...
Страница 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Страница 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Страница 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Страница 385: ...GD32F20x User Manual 385 ...
Страница 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...