ST STM32L4+ Series Reference Manual page 2134

USB on-the-go full-speed (OTG_FS)
56.15.9 OTG receive status debug read [alternate] (OTG_GRXSTSR)
Address offset for read: 0x01C
Reset value: 0x0000 0000
This description is for register OTG_GRXSTSR in Host mode.
A read to the receive status debug read register returns the contents of the top of the
receive FIFO.
The core ignores the receive status read when the receive FIFO is empty and returns a
value of 0x0000 0000.
31 30 29
Res. Res. Res. Res.
15 14 13
DPID
r r r
Bits 31:21 Reserved, must be kept at reset value.
Bits 20:17 PKTSTS[3:0]: Packet status
Bits 16:15 DPID[1:0]: Data PID
Bits 14:4 BCNT[10:0]: Byte count
Bits 3:0 CHNUM[3:0]: Channel number
2134/2301
28 27 26 25
Res. Res. Res.
12 11 10 9
BCNT[10:0]
r r r r
Indicates the status of the received packet
0010: IN data packet received
0011: IN transfer completed (triggers an interrupt)
0101: Data toggle error (triggers an interrupt)
0111: Channel halted (triggers an interrupt)
Others: Reserved
Indicates the data PID of the received packet
00: DATA0
10: DATA1
Indicates the byte count of the received IN data packet.
Indicates the channel number to which the current received packet belongs.
24 23 22
Res. Res. Res.
8 7 6
r r r
RM0432 Rev 6
21 20 19 18
Res. PKTSTS[3:0]
r r r
5 4 3 2
CHNUM[3:0]
r r r r
RM0432
17 16
DPID
r r
1 0
r r