What is Calibrationb Memory of a PIC?

[ericmar]

As above.

May I know wats the Calibration Memory of a PIC?
How do I find out wat value to program if I accidentally erase a PIC's calibration memory?


Thanks,
Eric Mar

 

[vaidyasp1]

Go through the datasheets of that microcontroller you will be able to know the configuration bits settings..

 

[rkodaira]

Some PICmicro have an internal oscillator trimmable by a value stored in the OSCCAL register. The factory stores an optimum value (for the nominal oscillator frequency) in the last position of the program memory as a RETLW opcode plus the calibration value itself. This value should be recalled by a CALL instruction and moved to the OSCCAL register. If you don´t use the internal oscillator or don´t need clock precision, you should not be worried about it. If you mind using the internal oscillator with some precision (not so much) and you lost the original contents of the last program memory position, writing a simple program can help you to recover this value. Write a program that should output a defined frequency at a pin (I/O port) using any value in the OSCCAL register. Make some routines to change this value by pushing another two buttons (one for increment and one for decrement the value) and store it in an eeprom position. When you find an acceptable value, just read the eeprom contents, combine with the RETLW opcode bits and write this word when burning the PIC.

 

[haseebcu]

Such spes are always on data sheet