There are other mcu's that you can use to do the precision timing. An SX chip (50 MIPS) bit banging with an interrupt can be used in conjunction with a PIC UART to update and control the SX . I am sure you have timing position sensors, feed those into the SX to trigger the next set of pulses. I have a brushless 3-Phase motor made up of the above mentioned, my motor spins at 30,000 rpm (variable speed) using zero crossing comparators for feedback.


Nick