Vilefly Thanks for the pics. They give some good hints.
Did the dwell time input decrease gradually with rpm increase.
If that is the case it can be calculated from the low res input or be a function of it. If that scaling can be turned off there will be always 5ms dwell available. Engine will run like crap at high rpm though but with 8 coils will be fine.
What some of you miss is that there is always 90 degree charging time for the coil available, and that doesn`t depend on commanded spark advance.
At 6000 rpm that will be 2.5ms between pulses.

Can I assume that 5 volts on the est charge the coil and 0 volts fires the coil.
I guess there is end of spark time just like end of injection and dwell is controlled by similar means.
End of dwell time is calculated to happen at commanded spark advance degrees.