Posted on February 18, 2014 at 18:24Ok,sung.chen_chung, thanks for your answer, i'll try to fix that.
But, i still have a question about VirtualCOMPort example of
STM32_USB-FS-Device_Lib_V4.0.0. in Readme file it says that:
This demo is using two different methods for the IN and OUT transfers in order
to manage the data rate difference between USB and USART buses:
- OUT transfers (from Host to Device):
When a packet is received from the host on the OUT pipe (EP3), the Endpoint
callback function is called when the transfer is complete and all the received
data are then sent through USART peripheral in polling mode. This allows all
incoming OUT packets to be NAKed till the current packet is completely transferred
through the USART interface.
- IN transfers (from Device to Host):
For IN data, a large circular buffer is used. USART and USB respectively write
and read to/from this buffer independently.
USART RXNE interrupt is used to write data into the buffer. This interrupt
has the highest priority, which allows to avoid overrun and data loss conditions.
USB IN endpoint (EP1) is written with the received data into the SOF interrupt
callback.
I can't find the routines that handles this. There is only the function that handles EVAL_COM1 global interrupt request.
