Datasheet

© 2011 Microchip Technology Inc. DS70143E-page 149
dsPIC30F6011A/6012A/6013A/6014A
20.2.8 PROTECTION AGAINST
ACCIDENTAL WRITES TO OSCCON
A write to the OSCCON register is intentionally made
difficult because it controls clock switching and clock
scaling.
To write to the OSCCON low byte, the following code
sequence must be executed without any other
instructions in between:
Byte Write 0x46 to OSCCON low
Byte Write 0x57 to OSCCON low
Byte write is allowed for one instruction cycle. Write the
desired value or use bit manipulation instruction.
To write to the OSCCON high byte, the following
instructions must be executed without any other
instructions in between:
Byte Write 0x78 to OSCCON high
Byte Write 0x9A to OSCCON high
Byte write is allowed for one instruction cycle. Write the
desired value or use bit manipulation instruction.
20.3 Oscillator Control Registers
The oscillators are controlled with two SFRs,
OSCCON and OSCTUN and one Configuration
register, FOSC.
Note: The description of the OSCCON and
OSCTUN SFRs, as well as the FOSC
Configuration register provided in this
section are applicable only to the
dsPIC30F6011A/6012A/6013A/6014A
devices in the dsPIC30F product family.