Content originally posted in LPCWare by wdawson61 on Fri Aug 26 08:46:21 MST 2011
Linux build v 4.05 (bld 113)
LPC1758 custom hardware
Hi.
I'm trying to dig into why a rather large application ~ 128k runs fine with no optimization but starts having issues when ANY compiler optimizations are enabled.
Its actually a bi-directional parallel interface to a DSP implemented using GPIOs that breaks. I've looked at the GPIO signals with a scope but they don't appear to be changed significantly between the optimized and non-optimized versions of running code. 2 of the GPIOs are triggering interrupts to the LPC1758 when data is sent / acknowledged by the DSP. I'm not really using any wait loops other than sticking a few no-ops here and there to stretch some signals. But again, they don't appear to be distorted between the optimized and non-optimized versions.
Any thoughts on how to nail this down would be greatly appreciated!!
-Wade
