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ILLEGAL_ISR w/ F28335

Started by Joseph Boike August 25, 2008
Hi,
I'm fairly new to DSPs and TI's development tools.
I've inherited a project that I'm having a problem with an ILLEGAL_ISR.
I'm using CCS 3.3 (sp 10)w/ DSP/BIOS 5_32_04 and code gen tools 5.0.2.
The project I inherited runs on a 'F2812 (compiled w/ older tools and CCS).
My job is to triple the calculations and get itto run on new h/w based on the F28335.
I have a h/w interrupt that reads the ADC inputs every 260.4uS. (Takes ~30uS).
I have 4 periodic functions (in DSP/BIOS lingo) that run every 1ms and take ~500uS.
After every 64 readings the ADC ISR will post a SWI w/ the SWI_post() command.
If I comment out most of the routine called be the SWI everything runs fine..
As I add back instructions, the code still works until the duration of the SWI approaches 1ms at which point the code runs for a few seconds to a few minutes (the longer the SWI routine, the faster the problem) then hits the ILLEGAL_ISR. The illegal instruction always is in my swi routine. I'm running from ram (internal for the ISR and PRD routines, external for most of the rest of the code). Most of the data is located in external ram w/ some in internal. Any suggestions would be greatly appreciated.
Regards,
Joe