Hard Fault when processing USB class requests

lpcware — Wed, 15 Jun 2016 16:52:06 GMT

Content originally posted in LPCWare by m-kondo on Thu Mar 28 04:26:02 MST 2013
Hello,

I am trying to implement USB test & measurement class on my MCB4300 (LPC4357) board as device mode using KEIL RTL and RL-USB. But when after processing a class request in the usbd_cls_if_req() callback function, a Hard Fault is always generated.

Actually in the cls_if_req()function, a class request (device-to-host) comes, set up the out-going (EP0-IN) data stage, then calls USBD_DataInStage() finishing with __TRUE return. The data stage is actually sent back to the host only at the first time, but after returning from usbd_cls_if_req(), a Hard Fault will be generated inside USB_CM.lib. Both USB0(HS) and USB1(FS) generate this problem.

As for std requests, there is no probrem at all, but as soon as returning a data-stage from inside usbd_cls_if_req(), the program falls into Hard Fault. I also tried exactly the same approach with MCBSTM32F400 (STM32F407) board and there was no such problem.

Can anybody please help me?

thanks
Makoto Kondo

topic Hard Fault when processing USB class requests in LPC Microcontrollers

Hard Fault when processing USB class requests