Yesterday i saw a board designed using PIC16f877A. They had a regular crystal oscilator of 8 MHZ but below that they had 32khz crystal with 33pf capacitor. now that board was a stopwatch so it has to do something with Time calculations.
First i thought why they had installed two crystals but later exploring it i thought it is for the time calculations. Any hint about it?
Note there was nothing else to calculate time just the rest of controllers pin controlled seven segment.
As above, the 32k crystal on TIMER1 is used for the RTC, while the 8MHz is used to control how fast the program instructions is run. The 32k oscillator can run even when the rest of the PIC is in sleep mode, which means that the PIC is basically switched off, but can still keep track of the time.