Microchip Technology DV164136 Data Sheet
© 2008 Microchip Technology Inc.
DS39646C-page 199
PIC18F8722 FAMILY
FIGURE 18-8:
PWM DIRECTION CHANGE
FIGURE 18-9:
PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
(1)
DC
Period
(1)
SIGNAL
Note
1: The direction bit in the ECCP1 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
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 T
OSC
or 64 T
OSC
, 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
P1B
P1C
P1D
External Switch D
Potential
Shoot-Through
Current
Note
1: All signals are shown as active-high.
2: t
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