70291E Datasheet, PDF (150/436 Pages) Microchip Technology – High-Performance, 16-bit Digital Signal Controllers

dsPIC33FJ32MC302/304, dsPIC33FJ64MCX02/X04 AND dsPIC33FJ128MCX02/X04
REGISTER 9-1: OSCCON: OSCILLATOR CONTROL REGISTER^(1,3) (CONTINUED)
bit 3
CF: Clock Fail Detect bit (read/clear by application)
1 = FSCM has detected clock failure
0 = FSCM has not detected clock failure
bit 2
Unimplemented: Read as ‘0’
bit 1
LPOSCEN: Secondary (LP) Oscillator Enable bit
1 = Enable secondary oscillator
0 = Disable secondary oscillator
bit 0
OSWEN: Oscillator Switch Enable bit
1 = Request oscillator switch to selection specified by NOSC<2:0> bits
0 = Oscillator switch is complete
Note 1:
2:
3:
Writes to this register require an unlock sequence. Refer to Section 39. “Oscillator (Part III)” (DS70216)
in the “dsPIC33F/PIC24H Family Reference Manual” (available from the Microchip web site) for details.
Direct clock switches between any primary oscillator mode with PLL and FRCPLL mode are not permitted.
This applies to clock switches in either direction. In these instances, the application must switch to FRC
mode as a transition clock source between the two PLL modes.
This register is reset only on a Power-on Reset (POR).
DS70291E-page 150
© 2011 Microchip Technology Inc.