ST STM32L4x6 User Manual

DocID024597 Rev 3 1583/1693
RM0351 USB on-the-go full-speed (OTG_FS)
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43.15.50 OTG device IN endpoint-x transfer size register (OTG_DIEPTSIZx)
(x = 1..5 , where x= Endpoint_number)
Address offset: 0x910 + (Endpoint_number × 0x20)
Reset value: 0x0000 0000
The application must modify this register before enabling the endpoint. Once the endpoint is
enabled using the Endpoint enable bit in the OTG_DIEPCTLx registers (EPENA bit in
OTG_DIEPCTLx), the core modifies this register. The application can only read this register
once the core has cleared the Endpoint enable bit.
Bit 19 PKTCNT: Packet count
This field is decremented to zero after a packet is written into the Rx FIFO.
Bits 18:7 Reserved, must be kept at reset value.
Bits 6:0 XFRSIZ: Transfer size
Indicates the transfer size in bytes for endpoint 0. The core interrupts the application only
after it has exhausted the transfer size amount of data. The transfer size can be set to the
maximum packet size of the endpoint, to be interrupted at the end of each packet.
The core decrements this field every time a packet is read from the Rx FIFO and written to
the external memory.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Res. MCNT PKTCNT XFRSIZ
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
1514131211109876543210
XFRSIZ
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bit 31 Reserved, must be kept at reset value.
Bits 30:29 MCNT: Multi count
For periodic IN endpoints, this field indicates the number of packets that must be transmitted
per frame on the USB. The core uses this field to calculate the data PID for isochronous IN
endpoints.
01: 1 packet
10: 2 packets
11: 3 packets
Bit 28:19 PKTCNT: Packet count
Indicates the total number of USB packets that constitute the Transfer Size amount of data
for this endpoint.
This field is decremented every time a packet (maximum size or short packet) is read from
the Tx FIFO.
Bits 18:0 XFRSIZ: Transfer size
This field contains the transfer size in bytes for the current endpoint. The core only interrupts
the application after it has exhausted the transfer size amount of data. The transfer size can
be set to the maximum packet size of the endpoint, to be interrupted at the end of each
packet.
The core decrements this field every time a packet from the external memory is written to the
Tx FIFO.

ST STM32L4x6 Specifications

General

Brand	ST
Model	STM32L4x6
Category	Microcontrollers
Language	English