PIC18F2331 MICROCHIP [Microchip Technology], PIC18F2331 Datasheet - Page 187

• Manufacturer Part Number: PIC18F2331
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D
• Manufacturer: MICROCHIP [Microchip Technology]

FIGURE 17-4:
The PWM time base can be configured for four different
modes of operation:
• Free Running mode
• Single-shot mode
• Continuous Up/Down Count mode
• Continuous Up/Down Count mode with interrupts
These
PTMOD1:PTMOD0 bits in the PTCON0 register. The
Free Running mode produces edge-aligned PWM
generation. The up/down counting modes produce
center-aligned PWM generation. The Single-shot
mode allows the PWM module to support pulse control
of certain electronically commutated motors (ECMs)
and produces edge-aligned operation.
 2003 Microchip Technology Inc.
for double updates
four
F
OSC
modes
/4
PWM TIME BASE BLOCK DIAGRAM
Comparator
Zero
match
Period
match
PTPER Buffer
are
1:1, 1:4, 1:16, 1:64
PTPER
Prescaler
PTMR Register
selected
Comparator
Period load
Update disable (UDIS)
Period match
PIC18F2331/2431/4331/4431
by
Period match
PTMOD1
Zero match
Postscaler
1:1 - 1:16
PTMOD1
PTMOD0
PTMOD1
PTMOD0
Zero match
Preliminary
the
Timer RESET
Direction
Up/Down
Control
Interrupt
Control
Control
Timer
Clock
PTMR Clock
PTDIR
PTEN
PTMR clock
PTIF
Duty Cycle Load
DS39616B-page 185