2.3 LCD Charge Pump Watchdog Timer
The LCD module includes a built-in Watchdog Timer that
monitors the charge pump to ensure that the internal capacitors
have completely discharged before disabling or resetting.
Without the LCD Charge Pump Watchdog Timer Reset state a disable
of the charge pump will cause the I/O pins to switch internally
from LCD to GPIO. The charge pump Watchdog Timer provides a time
out period during which the capacitors can discharge. Once the
time out period has expired, it will switch the I/O pins from
LCD to GPIO and perform the Reset or disable. It is recommended
to leave the charge pump Watchdog Timer enabled to prevent
damage to the LCD charge pump in the event where there is still
excess charge stored on the internal capacitors. This is done by
clearing the CPWDT bit of LCDVCON2 (CPWDT = 0
).
If the user wishes to disable this bit to reduce the amount of
time it takes to Reset or disable the LCD charge pump, this can
be done by setting the CPWDT bit (CPWDT = 1
).
Although disabling the charge pump Watchdog Timer may reduce
Reset time, it poses a risk of the charge pump not completely
discharging before being Reset or disabled, which could
potentially damage the device internally.