Posted on November 15, 2014 at 10:21As user.st said, I tried to slow down AHB freq from DIV1 to DIV4 (42MHz in stm32f407), and the problem is resolved, both transmitting and receiving are working fine now. I believe this problem is a problem of har...

Posted on November 15, 2014 at 08:28I met the same problem with CubeF4 on STM32F407. As mentioned above, USBH_CDC_Transmit sometimes can not send data out. In my tests, it seemed that this problem will cause data queued in txfifo, and later USBH_CDC...