DSPIC30F2010 MICROCHIP [Microchip Technology], DSPIC30F2010 Datasheet - Page 90

• Manufacturer Part Number: DSPIC30F2010
• Description: High-Performance, 16-Bit Digital Signal Controllers
• Manufacturer: MICROCHIP [Microchip Technology]

dsPIC30F2010
14.11 PWM Output and Polarity Control
There are three device Configuration bits associated
with the PWM module that provide PWM output pin
control:
• HPOL Configuration bit
• LPOL Configuration bit
• PWMPIN Configuration bit
These three bits in the FPORBOR Configuration regis-
ter (see Section 21) work in conjunction with the three
PWM enable bits (PWMEN<3:1>) located in the
PWMCON1 SFR. The Configuration bits and PWM
enable bits ensure that the PWM pins are in the correct
states after a device Reset occurs. The PWMPIN con-
figuration fuse allows the PWM module outputs to be
optionally enabled on a device Reset. If PWMPIN = 0,
the PWM outputs will be driven to their inactive states
at Reset. If PWMPIN = 1 (default), the PWM outputs
will be tri-stated. The HPOL bit specifies the polarity for
the PWMxH outputs, whereas the LPOL bit specifies
the polarity for the PWMxL outputs.
14.11.1
The PEN<3:1>H and PEN<3:1>L control bits in the
PWMCON1 SFR enable each high PWM output pin
and each low PWM output pin, respectively. If a partic-
ular PWM output pin not enabled, it is treated as a
general purpose I/O pin.
14.12 PWM FLTA Pins
There is one FLTA pin (FLTA) associated with the PWM
module. When asserted, this pin can optionally drive
each of the PWM I/O pins to a defined state.
14.12.1
The FLTACON SFR has 4 control bits that determine
whether a particular pair of PWM I/O pins is to be con-
trolled by the FLTA input pin. To enable a specific PWM
I/O pin pair for FLTA overrides, the corresponding bit
should be set in the FLTACON register.
If all enable bits are cleared in the FLTACON register,
then the FLTA input pin has no effect on the PWM mod-
ule and the pin may be used as a general purpose
interrupt or I/O pin.
14.12.2
The FLTACON special function register has 8 bits that
determine the state of each PWM I/O pin when it is
overridden by a FLTA input. When these bits are
DS70118G-page 88
Note:
OUTPUT PIN CONTROL
FAULT PIN ENABLE BITS
The FLTA pin logic can operate indepen-
dent of the PWM logic. If all the enable bits
in the FLTACON register are cleared, then
the FLTA pin(s) could be used as general
purpose interrupt pin(s). Each FLTA pin
has an interrupt vector, interrupt flag bit
and interrupt priority bits associated with it.
FAULT STATES
cleared, the PWM I/O pin is driven to the inactive state.
If the bit is set, the PWM I/O pin will be driven to the
active state. The active and inactive states are refer-
enced to the polarity defined for each PWM I/O pin
(HPOL and LPOL polarity control bits).
14.12.3
The FLTA input pin has two modes of operation:
• Latched Mode: When the FLTA pin is driven low,
• Cycle-by-Cycle Mode: When the FLTA input pin
The Operating mode for the FLTA input pin is selected
using the FLTAM control bit in the FLTACON Special
Function Register.
The FLTA pin can be controlled manually in software.
14.13 PWM Update Lockout
For a complex PWM application, the user may need to
write up to four duty cycle registers and the time base
period register, PTPER, at a given time. In some appli-
cations, it is important that all buffer registers be written
before the new duty cycle and period values are loaded
for use by the module.
The PWM update lockout feature is enabled by setting
the UDIS control bit in the PWMCON2 SFR. The UDIS
bit affects all duty cycle buffer registers and the PWM
time base period buffer, PTPER. No duty cycle
changes or period value changes will have effect while
UDIS = 1.
the PWM outputs will go to the states defined in
the FLTACON register. The PWM outputs will
remain in this state until the FLTA pin is driven
high and the corresponding interrupt flag has
been cleared in software. When both of these
actions have occurred, the PWM outputs will
return to normal operation at the beginning of the
next PWM cycle or half-cycle boundary. If the
interrupt flag is cleared before the FLTA condition
ends, the PWM module will wait until the FLTA pin
is no longer asserted to restore the outputs.
is driven low, the PWM outputs remain in the
defined FLTA states for as long as the FLTA pin is
held low. After the FLTA pin is driven high, the
PWM outputs return to normal operation at the
beginning of the following PWM cycle or
half-cycle boundary.
FAULT INPUT MODES
© 2006 Microchip Technology Inc.