What is a PIC 12f629/12f675?
The PIC 12F629 and 12F675 devices have an internal 4Mhz oscillator that enables the devices to be used without an external crystal or RC network. This frees up one or two pins for I/O use and allows the device to be built into minimum component count designs.
How do I calibrate my Pic 12f629 or 12f675?
The PIC 12F629 and 12F675 have a factory set oscillator calibration value written to the last program memory location during manufacture. When programming the PIC the programmer software should read this value out, merge it with the program data being written to the PIC, and then write it back.
What is the frequency of the oscillator in the Pic?
The frequency of the internal oscillator in the PIC varies with both changes in temperature and supply voltage. As the supply voltage increases the frequency decreases slightly. When switch S1 is open the 5 volt supply to the PIC is dropped across the two diodes to about 3.4 volts.
Do I need a PICkit2 programmer?
Therefore I would now recommend you get a PICkit2 programmer and then you’ll never need to worry about the OSCCAL word getting erased ever again.