Talk:UBW32 Blue Banana Electronics
Cortex M3 as I initially believed is that even Cortex M3 has some interesting features (like 7 DMA channels) the main thing mcu need to do is bit-bang the pins to drive steppers and this is something PIC is just faster then Cortex M3.
I am developing with the Cortex-M3 and I found that I can't run my stepper motors at more than 100us period each step pulse, for pololu drivers. My Cortex-M3 running at 100MHz, gives ticks of 10ns, so, 10.000 times more the needed for stepper motor pulses. So, there is no worry about what you say.