STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

RM0008
USB on-the-go full-speed (OTG_FS)
c) Setup stage done pattern:
PKTSTS = Setup Stage Done, BCNT = 0x0, EPNUM = Control EP Num,
DPID = Don’t Care (0b00).
These data indicate that the Setup stage for the specified endpoint has completed
and the Data stage has started. After this entry is popped from the receive FIFO,
the core asserts a Setup interrupt on the specified control OUT endpoint.
d) Data OUT packet pattern:
PKTSTS = DataOUT, BCNT = size of the received data OUT packet (0 BCNT
1 024), EPNUM = EPNUM on which the packet was received, DPID = Actual
Data PID.
e) Data transfer completed pattern:
PKTSTS = Data OUT Transfer Done, BCNT = 0x0, EPNUM = OUT EP Num
on which the data transfer is complete, DPID = Don’t Care (0b00).
These data indicate that an OUT data transfer for the specified OUT endpoint has
completed. After this entry is popped from the receive FIFO, the core asserts a
Transfer Completed interrupt on the specified OUT endpoint.
5. After the data payload is popped from the receive FIFO, the RXFLVL interrupt
(OTG_FS_GINTSTS) must be unmasked.
6. Steps 1–5 are repeated every time the application detects assertion of the interrupt line
due to RXFLVL in OTG_FS_GINTSTS. Reading an empty receive FIFO can result in
undefined core behavior.
Figure 276 provides a flowchart of the above procedure.
Figure 276. Receive FIFO packet read in slave mode
wait until RXFLVL in OTG_FS_GINTSTSG
rd_data = rd_reg (OTG_FS_GRXSTSP);
Y
rd_data.BCNT = 0
rcv_out_pkt()
N
packet
store in
memory
mem[0:dword_cnt-1] =
rd_rxfifo(rd_data.EPNUM,
dword_cnt)
dword_cnt =
BCNT[11:2] +
(BCNT[1] | BCNT[1])
ai15677
● SETUP transactions
This section describes how the core handles SETUP packets and the application’s
sequence for handling SETUP transactions.
Doc ID 13902 Rev 9 813/995