PIC18F25K20T-ISS Datasheet, PDF (184/456 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F2XK20/4XK20
Note 1: The auto-shutdown condition is a
level-based signal, not an edge-based
signal. As long as the level is present, the
auto-shutdown will persist.
2: Writing to the ECCPASE bit is disabled
while an auto-shutdown condition
persists.
3: Once the auto-shutdown condition has
been removed and the PWM restarted
(either through firmware or auto-restart)
the PWM signal will always restart at the
beginning of the next PWM period.
FIGURE 16-10: PWM AUTO-SHUTDOWN WITH FIRMWARE RESTART (PRSEN = 0)
Shutdown Event
PWM Period
ECCPASE bit
PWM Activity
Start of
PWM Period
Normal PWM
Shutdown
Event Occurs
ECCPASE
Cleared by
Shutdown Firmware PWM
Event Clears
Resumes
16.4.5 AUTO-RESTART MODE
The Enhanced PWM can be configured to automati-
cally restart the PWM signal once the auto-shutdown
condition has been removed. Auto-restart is enabled by
setting the PRSEN bit in the PWM1CON register.
If auto-restart is enabled, the ECCPASE bit will remain
set as long as the auto-shutdown condition is active.
When the auto-shutdown condition is removed, the
ECCPASE bit will be cleared via hardware and normal
operation will resume.
FIGURE 16-11: PWM AUTO-SHUTDOWN WITH AUTO-RESTART ENABLED (PRSEN = 1)
Shutdown Event
PWM Period
ECCPASE bit
PWM Activity
Start of
PWM Period
Normal PWM
Shutdown Shutdown
Event Occurs Event Clears
PWM
Resumes
DS41303G-page 184
 2010 Microchip Technology Inc.