Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
613
/
631
Bit Field
Name
Description
1
、
Software can read and write this bit, but writing 0 is invalid, and writing 1
toggles this bit.
2
、
Control endpoint, the hardware will set this bit after the USB module correctly
receives the PID SETUP token packet.
3
、
In isochronous transfer, hardware toggles this bit just after the end of data
packet transmission.
5
:
4
STS_TX[1:0]
Send status
This bit indicates the current state of the endpoint, Table 26-7 lists the available states
of the endpoint. When a correct IN transaction completes, the hardware sets this bit to
the NAK state.
Note:
1
、
Software can read and write this bit, but writing 0 is invalid, and writing 1
toggles this bit.
2
、
Double-buffered bulk endpoint, which controls the transmission status according
to the buffer status used, refer to section 26.4.3.
3
、
Isochronous endpoint, the hardware will not change the state of the endpoint
after the transaction is successfully completed.
3
:
0
EPADDR[3:0]
Endpoint address
This bit indicates the destination endpoint of the communication and must be written
before enabling the corresponding endpoint.
Note:
1
、
When the USB module receives the USB bus reset signal, or USB_CTRL.FRST = 1, the USB module will be reset.
Except for the CTRS_RX and CTRS_TX bits that remain unchanged to process the following USB transfer, all
other bits are reset.
Table 26-6 Receive status code
STS_RX[1:0]
Description
00
DISABLED: ignore all receive requests for this endpoint
01
STALL: the status of the handshake packet is STALL
10
NAK: the status of the handshake packet is NAK
11
VALID: endpoints can be used to receive
Table 26-7 Send status code
STS_TX[1:0]
Description
00
DISABLED: ignore all send requests for this endpoint
01
STALL: the status of the handshake packet is STALL
10
NAK: the status of the handshake packet is NAK
11
VALID: endpoints can be used to send