dctowery wrote on Sunday, July 10, 2011:
Hi, I have a naive question that I can’t answer myself because my dev board blew up and I’m waiting on a new one. I’m completely new to programming ColdFires at the register level, and I’m trying to antipicate a problem that may crop up.
I’m coding for the M52221Demo board (FreeScale ColdFire V2 MCF52221) and I need to configure a couple of IRQ lines in the EdgePort module. According to the FreeScale manual, the following registers can only be accessed in Supervisor mode:
EPPAR (pin assignment reg), EPDDR (data direction reg), EPIER (interrupt enable reg).
The demo code for the 52221 doesn’t illustrate any use of IRQs. How do I best access these registers to configure the IRQ lines? Do I have to set Supervisor Mode? If so, does FreeRTOS provide any easy way to do this? If not, I guess I have to mess with the System Control Module - can anyone summarize the steps I need to take there to enter and exit Supervisor mode? Any example code (or just pointers to the best sections to read in the 52221 Ref Manual) would be appreciated.