AFAIK the Gecko G540 spindle interface output voltage is isolated and does not depend on the interface signal levels, it depends on the externally supplied spindle analog power (and the PWM duty cycle)
And yes, the g540 configuration had a PWM generator on pin 14:
Code:
IO Connections for P3
Pin# I/O Pri. func Sec. func Chan Pin func Pin Dir
1 0 IOPort None
14 1 IOPort PWMGen 0 PWM (Out)
2 2 IOPort StepGen 0 Step (Out)
15 3 IOPort None
3 4 IOPort StepGen 0 Dir (Out)
16 5 IOPort StepGen 4 Step (Out)
4 6 IOPort StepGen 1 Step (Out)
17 7 IOPort None
5 8 IOPort StepGen 1 Dir (Out)
6 9 IOPort StepGen 2 Step (Out)
7 10 IOPort StepGen 2 Dir (Out)
8 11 IOPort StepGen 3 Step (Out)
9 12 IOPort StepGen 3 Dir (Out)
10 13 IOPort QCount 0 Quad-A (In)
11 14 IOPort QCount 0 Quad-B (In)
12 15 IOPort QCount 0 Quad-IDX (In)
13 16 IOPort None
