lpcware

Hard error with MCB1800 and USB PROM version and mouse example

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by Skyle on Tue Jan 08 16:30:58 MST 2013
I want to use the built in ROM version of the drivers, i tested the mouse example mainly as a first simple approach. It works fine in the IAR environmnet, but there it builds for RAM. I ported into an Eclipse environment with GCC. The non ROM version works fine with FreeRTOS. When i switched to using the ROM version I got a hard error exception.

After going back to the clean non RTOS example, but still compiled with GCC., I still got the hard error. I have tried to figure out what could be different between the comopilers, have studied the descriptor structures in detail trying to find some "packing" differences.

After removing the "const" and "PROGMEM" atributes on the descriptors definitions, getting them, into RAM rather than in flash, it now seems to work.

As I see it there can be 2 possibilities for this, either tha ROM stack tries to write something in the descriptors, or the ROM version cannot read for example 8 bit elements from flash.

What is wrong here?

I am using the latest version of the USBlib stack.

Outcomes