![](http://datasheet.mmic.net.cn/30000/MQ83C154DXXX-25-883R_datasheet_2377229/MQ83C154DXXX-25-883R_705.png)
705
6384E–ATARM–05-Feb-10
AT91SAM9G20
Bulk and interrupt endpoints: This bit notifies the host that the endpoint is halted.
The host acknowledges the STALL, device firmware is notified by the STALLSENT flag.
RX_DATA_BK1: Receive Data Bank 1 (only used by endpoints with ping-pong attributes)
This flag generates an interrupt while it is set to one.
Write (Cleared by the firmware):
0 = Notifies USB device that data have been read in the FIFO’s Bank 1.
1 = To leave the read value unchanged.
Read (Set by the USB peripheral):
0 = No data packet has been received in the FIFO's Bank 1.
1 = A data packet has been received, it has been stored in FIFO's Bank 1.
When the device firmware has polled this bit or has been interrupted by this signal, it must transfer data from the FIFO to
microcontroller memory. The number of bytes received is available in RXBYTECNT field. Bank 1 FIFO values are read
through UDP_FDRx register. Once a transfer is done, the device firmware must release Bank 1 to the USB device by clear-
ing RX_DATA_BK1.
After setting or clearing this bit, a wait time of 3 UDPCK clock cycles and 3 peripheral clock cycles is required before
accessing DPR.
DIR: Transfer Direction (only available for control endpoints)
Read-write
0 = Allows Data OUT transactions in the control data stage.
1 = Enables Data IN transactions in the control data stage.
Refer to Chapter 8.5.3 of the Universal Serial Bus Specification, Rev. 2.0 for more information on the control data stage.
This bit must be set before UDP_CSRx/RXSETUP is cleared at the end of the setup stage. According to the request sent in
the setup data packet, the data stage is either a device to host (DIR = 1) or host to device (DIR = 0) data transfer. It is not
necessary to check this bit to reverse direction for the status stage.
EPTYPE[2:0]: Endpoint Type
Read-write
000
Control
001
Isochronous OUT
101
Isochronous IN
010
Bulk OUT
110
Bulk IN
011
Interrupt OUT
111
Interrupt IN