
2004 Microchip Technology Inc.
DS30491C-page 183
PIC18F6585/8585/6680/8680
FIGURE 16-9:
PWM DIRECTION CHANGE
FIGURE 16-10:
PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
DC
Period(1)
SIGNAL
Note
1:
The direction bit in the CCP1 Control register (CCP1CON<7>) is written any time during the PWM cycle.
2:
When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle at inter-
vals of 4 TOSC, 16 TOSC or 64 TOSC, depending on the Timer2 prescaler value. The modulated P1B and P1D
signals are inactive at this time.
Period
(Note 2)
P1A (Active-High)
P1B (Active-High)
P1C (Active-High)
P1D (Active-High)
DC
Forward Period
Reverse Period
P1A
tON
tOFF
t = tOFF – tON
P1B
P1C
P1D
External Switch D
Potential
Shoot-Through
Current
Note
1: All signals are shown as active-high.
2: tON is the turn on delay of power switch QC and its driver.
3: tOFF is the turn off delay of power switch QD and its driver.
External Switch C
t1
DC