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.