Datasheet

PIC12F508/509/16F505
DS41236B-page 24 Preliminary © 2005 Microchip Technology Inc.
4.6 OSCCAL Register
The Oscillator Calibration (OSCCAL) register is used to
calibrate the internal precision 4 MHz oscillator. It
contains seven bits for calibration
.
After you move in the calibration constant, do not
change the value. See Section 7.2.5 “Internal 4 MHz
RC Oscillator”.
REGISTER 4-5: OSCCAL REGISTER (ADDRESS: 05h)
Note: Erasing the device will also erase the pre-
programmed internal calibration value for
the internal oscillator. The calibration
value must be read prior to erasing the
part so it can be reprogrammed correctly
later.
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-0
CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0
—
bit 7 bit 0
bit 7-1 CAL<6:0>: Oscillator Calibration bits
0111111 = Maximum frequency
•
•
•
0000001
0000000 = Center frequency
1111111
•
•
•
1000000 = Minimum frequency
bit 0 Unimplemented: Read as ‘0’
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown