PIC18F2331-E/ML MICROCHIP [Microchip Technology], PIC18F2331-E/ML Datasheet - Page 198

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

PIC18F2331/2431/4331/4431
18.11 PWM Output and Polarity Control
There are three device Configuration bits associated
with the PWM module that provide PWM output pin
control defined in the CONFIG3L Configuration
register. They are:
• HPOL
• LPOL
• PWMPIN
These three Configuration bits work in conjunction with
the three PWM Enable bits (PWMEN<2:0>) in the
PWMCON0 register. The Configuration bits and PWM
enable bits ensure that the PWM pins are in the correct
states after a device Reset occurs.
18.11.1
The PWMEN<2:0> control bits enable each PWM
output pin as required in the application.
All PWM I/O pins are general purpose I/O. When a pair
of pins are enabled for PWM output, the PORT and
TRIS registers controlling the pins are disabled. Refer
to
FIGURE 18-23:
DS39616D-page 198
Figure 18-23
OUTPUT PIN CONTROL
Note:
for details.
PWM Signal from Module
PWM Pin Enable
Data Bus
WR PORT
WR TRIS
RD TRIS
RD PORT
PWM I/O PIN BLOCK DIAGRAM
I/O pin has protection diodes to V
Data Latch
TRIS Latch
D
D
CK
CK
Q
Q
Q
Q
DD
and V
1
0
SS
. PWM polarity selection logic not shown for clarity.
18.11.2
The polarity of the PWM I/O pins is set during device
programming via the HPOL and LPOL Configuration
bits in the CONFIG3L Configuration register. The
HPOL Configuration bit sets the output polarity for the
high side PWM outputs: PWM1, PWM3, PWM5 and
PWM7. The polarity is active-low when HPOL is
cleared (= 0), and active-high when it is set (= 1).
The LPOL Configuration bit sets the output polarity for
the low side PWM outputs: PWM0, PWM2, PWM4 and
PWM6. As with HPOL, they are active-low when LPOL
is cleared and active-high when it is set.
All output signals generated by the PWM module are
referenced to the polarity control bits, including those
generated by Fault inputs or manual override (see
Section 18.10 “PWM Output
The default polarity Configuration bits have the PWM
I/O pins in active-high output polarity.
Q
EN
D
OUTPUT POLARITY CONTROL
V
V
P
N
DD
SS
 2010 Microchip Technology Inc.
Override”).
TTL or
Schmitt
Trigger
I/O Pin