PIC18F6525/6621/8525/8621
FIGURE 17-8:
PWM DIRECTION CHANGE
(1)
Period
Period
SIGNAL
P1A (Active-High)
P1B (Active-High)
DC
P1C (Active-High)
P1D (Active-High)
(Note 2)
DC
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
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.
FIGURE 17-9:
PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
Forward Period
Reverse Period
t1
(1)
(1)
P1A
P1B
DC
(1)
P1C
P1D
(1)
DC
(2)
t
ON
(1)
(1)
External Switch C
External Switch D
(3)
t
OFF
(2,3)
Potential
t = t
– t
ON
OFF
Shoot-Through
(1)
Current
Note 1: All signals are shown as active-high.
2:
3:
t
t
is the turn-on delay of power switch QC and its driver.
ON
is the turn-off delay of power switch QD and its driver.
OFF
2005 Microchip Technology Inc.
DS39612B-page 167
MICROCHIP [ MICROCHIP ]
