Datasheet

dsPIC33F
DS70165E-page 152 Preliminary © 2007 Microchip Technology Inc.
REGISTER 8-1: OSCCON: OSCILLATOR CONTROL REGISTER
U-0 R-0 R-0 R-0 U-0 R/W-y R/W-y R/W-y
—COSC<2:0>—NOSC<2:0>
bit 15 bit 8
R/W-0 U-0 R-0 U-0 R/C-0 U-0 R/W-0 R/W-0
CLKLOCK —LOCK—CF — LPOSCEN OSWEN
bit 7 bit 0
Legend: y = Value set from Configuration bits on POR
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
bit 15 Unimplemented: Read as ‘0’
bit 14-12 COSC<2:0>: Current Oscillator Selection bits (read-only)
000 = Fast RC oscillator (FRC)
001 = Fast RC oscillator (FRC) with PLL
010 = Primary oscillator (XT, HS, EC)
011 = Primary oscillator (XT, HS, EC) with PLL
100 = Secondary oscillator (SOSC)
101 = Low-Power RC oscillator (LPRC)
110 = Fast RC oscillator (FRC) with Divide-by-16
111 = Fast RC oscillator (FRC) with Divide-by-n
bit 11 Unimplemented: Read as ‘0’
bit 10-8 NOSC<2:0>: New Oscillator Selection bits
000 = Fast RC oscillator (FRC)
001 = Fast RC oscillator (FRC) with PLL
010 = Primary oscillator (XT, HS, EC)
011 = Primary oscillator (XT, HS, EC) with PLL
100 = Secondary oscillator (SOSC)
101 = Low-Power RC oscillator (LPRC)
110 = Fast RC oscillator (FRC) with Divide-by-16
111 = Fast RC oscillator (FRC) with Divide-by-n
bit 7 CLKLOCK: Clock Lock Enable bit
1 = If (FCKSM1 = 1), then clock and PLL configurations are locked.
If (FCKSM1 = 0), then clock and PLL configurations may be modified.
0 = Clock and PLL selections are not locked, configurations may be modified
bit 6 Unimplemented: Read as ‘0’
bit 5 LOCK: PLL Lock Status bit (read-only)
1 = Indicates that PLL is in lock, or PLL start-up timer is satisfied
0 = Indicates that PLL is out of lock, start-up timer is in progress or PLL is disabled
bit 4 Unimplemented: Read as ‘0’
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