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GD32F20x User Manual
946
Device OUT endpoint-x transfer length register (USBFS_DOEPxLEN) (x = 1..3,
where x = endpoint_number)
Address offset: (endpoint_number × 0x20)
Reset value: 0x0000 0000
This register has to be accessed by word (32-bit)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Rese
rve
d
RX
DP
ID/S
T
P
CN
T
[1
:0
]
P
CN
T
[9
:0
]
T
L
E
N[1
8
:1
6
]
r/rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
T
L
E
N[1
5
:0
]
rw
Bits
Fields
Descriptions
31
Reserved
Must be kept at reset value.
30:29
RXDPID[1:0]
STPCNT[1:0]
Received DATA PID (for isochronous OUT endpoints)
This field saves the PID of the latest received data packet on this endpoint.
00: DATA0
10: DATA1
Others: Reserved
SETUP packet count (for control OUT Endpoints.)
This field defines the maximum number of back-to-back SETUP packets this
endpoint can accept.
Program this field before SETUP transfers. Each time a back-to-back SETUP
packet is received, USBFS decreases this field by one. When this field reaches
zero, the BTBSTP flag in USBFS_DOEPxINTF register will be triggered.
00: 0 packet
01:1 packet
10: 2 packets
11: 3 packets
28:19
PCNT[9:0]
Packet count
The number of data packets desired to receive in a transfer.
Program this field before the endpoint is enabled. After the transfer starts, this field
is decreased automatically after each successful data packet reception on bus.
18:0
TLEN[18:0]
Transfer length
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...