Microchip Technology DM183021 Data Sheet

DS39616D-page 200

 2010 Microchip Technology Inc.

18.12.3

PWM OUTPUTS WHILE IN FAULT 
CONDITION

While in the Fault state (i.e., one or both FLTA and
FLTB inputs are active), the PWM output signals are
driven into their inactive states. The selection of which
PWM outputs are deactivated (while in the Fault state)
is determined by the FLTCON bit in the FLTCONFIG
register as follows:
• FLTCON = 1: When FLTA or FLTB is asserted, 

the PWM outputs (i.e., PWM<7:0>) are driven into 
their inactive state.

• FLTCON = 0: When FLTA or FLTB is asserted, 

only PWM<5:0> outputs are driven inactive, 
leaving PWM<7:6> activated.

18.12.4

PWM OUTPUTS IN DEBUG MODE

The BRFEN bit in the FLTCONFIG register controls the
simulation of a Fault condition, when a breakpoint is hit,
while debugging the application using an In-Circuit
Emulator (ICE) or an In-Circuit Debugger (ICD). Setting
the BRFEN to high, enables the Fault condition on
breakpoint, thus driving the PWM outputs to the inactive
state. This is done to avoid any continuous keeping of
status on the PWM pin, which may result in damage of
the power devices connected to the PWM outputs. 
If BRFEN = 0, the Fault condition on breakpoint is
disabled.

Disabling only three PWM channels and
leaving one PWM channel enabled when
in the Fault state, allows the flexibility to
have at least one PWM channel enabled.
None of the PWM outputs can be enabled
(driven with the PWM Duty Cycle
registers) while FLTCON = 1 and the Fault
condition is present.

It is highly recommended to enable the
Fault condition on breakpoint if a debug-
ging tool is used while developing the
firmware and high-power circuitry. When
the device is ready to program after
debugging the firmware, the BRFEN bit
can be disabled.