Datasheet

PIC18F2220/2320/4220/4320
DS39599G-page 148 © 2007 Microchip Technology Inc.
FIGURE 16-8: PWM DIRECTION CHANGE
FIGURE 16-9: PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
(1)
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 intervals of
4 T
OSC, 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
t
on
(2)
t
off
(3)
t = t
off
– t
on
(2,3)
P1B
P1C
P1D
External Switch D
Potential
Shoot-Through
Current
Note 1: All signals are shown as active-high.
2: t
on
is the turn-on delay of power switch QC and its driver.
3: t
off
is the turn-off delay of power switch QD and its driver.
External Switch C
t1
DC
DC