STM32F102C6 USB Issue

[jrwynne]

Posted on August 30, 2011 at 19:42

Attempting to reuse the USB library code and the code example for the virtual com port and basically the system (with a few changes) works as expected. However, we have a situation where sometimes when the host cannot unload the data fast enough from the device (i.e. the comm program running on the PC is running slow) that the USB system gets hung with USB_Tx_State high, the STAT_TX bits set such that transmissing should be running but the controller NACKing the host. We've tried isolating the issues between foreground and background (interrupt) manipulation of the common variables, but we still run into this problem. So, how can the STAT_TX bits be set (11) and the device still NACK the host?

#stm32f102c6-usb-virtual-cdc

[dtnaik26]

Posted on September 08, 2011 at 18:17

In the virtual com port example UART1 is used which does not support hardware flow control. I suggest pls use UART2 and also enable the hardware flow control . This may help you to resolve the issue.