GD32VF103 User Manual
507
a device sends a data packet and the packet length exceeds the endpoint
’s
maximum packet length.
7
USBER
USB Bus Error
The USB error flag is set when the following conditions occurs during receiving a
packet:
A received packet has a wrong CRC field
A stuff error detected on USB bus
Timeout when waiting for a response packet
6
Reserved
Must be kept at reset value
5
ACK
ACK
An ACK response is received or transmitted
4
NAK
NAK
A NAK response is received.
3
STALL
STALL
A STALL response is received.
2
Reserved
Must be kept at reset value
1
CH
Channel halted
This channel is disabled by a request, and it will not response to other requests
during the request processing.
0
TF
Transfer finished
All the transactions of this channel finish successfully, and no error occurs. For IN
channel, this flag will be triggered after PCNT bits in USBFS_HCHxLEN register
reach zero. For OUT channel, this flag will be triggered when software reads and
pops a TF status entry from the RxFIFO.
Host channel-x interrupt enable register (USBFS_HCHxINTEN) (x = 0..7, where
x = channel number)
Address offset: (channel_number × 0x20)
Reset value: 0x0000 0000
This register contains the interrupt enable bits for the flags in USBFS_HCHxINTF register. If
a bit in this register is set by software, the corresponding bit in USBFS_HCHxINTF register is
able to trigger a channel interrupt. The bits in this register are set and cleared by software.
This register has to be accessed by word (32-bit)