Yeah, I was hoping to get timer interrupt hints on my thread for Tone.cpp code. I've done timers on Uno and Maple, but Maple IO architecture is quite different from DUE. There is PWM timer code in
hardware/arduino/sam/cores/arduino/wiring_analog.c
but no interrupt code. The Timer/Counter support routines (no interrupt routines) are in
hardware/arduino/sam/system/libsam/source/tc.c
with the #define's in
hardware/arduino/sam/system/CMSIS/Device/ATMEL/sam3sd8/include/component/component_tc.h
The ISR handler's are named TCx_Handler(), e.g. TC0_Handler()
I'm guessing (don't have a DUE yet) that interrupt enable would be something like
tc->TC_CHANNEL[chan].TC_IER = TC_IER_CPCS;
but there is also an interrupt mask register TC_IMR?
not much help, but hopeful ...