Microchip Technology MA330016 Data Sheet
© 2007-2011 Microchip Technology Inc.
DS70290J-page 101
dsPIC33FJ32GP202/204 and dsPIC33FJ16GP304
8.3
Oscillator Control Registers
REGISTER 8-1:
OSCCON: OSCILLATOR CONTROL REGISTER
(1,3)
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>
(2)
bit 15
bit 8
R/W-0
R/W-0
R-0
U-0
R/C-0
U-0
R/W-0
R/W-0
CLKLOCK
IOLOCK
LOCK
—
CF
—
LPOSCEN
OSWEN
bit 7
bit 0
Legend:
y = Value set from Configuration bits on POR
C = Clear only bit
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)
111 = Fast RC oscillator (FRC) with Divide-by-n
110 = Fast RC oscillator (FRC) with Divide-by-16
101 = Low-Power RC oscillator (LPRC)
100 = Secondary oscillator (Sosc)
011 = Primary oscillator (XT, HS, EC) with PLL
010 = Primary oscillator (XT, HS, EC)
001 = Fast RC oscillator (FRC) with PLL
000 = Fast RC oscillator (FRC)
111 = Fast RC oscillator (FRC) with Divide-by-n
110 = Fast RC oscillator (FRC) with Divide-by-16
101 = Low-Power RC oscillator (LPRC)
100 = Secondary oscillator (Sosc)
011 = Primary oscillator (XT, HS, EC) with PLL
010 = Primary oscillator (XT, HS, EC)
001 = Fast RC oscillator (FRC) with PLL
000 = Fast RC oscillator (FRC)
bit 11
Unimplemented: Read as ‘0’
bit 10-8
NOSC<2:0>: New Oscillator Selection bits
(2)
111 = Fast RC oscillator (FRC) with Divide-by-n
110 = Fast RC oscillator (FRC) with Divide-by-16
101 = Low-Power RC oscillator (LPRC)
100 = Secondary oscillator (Sosc)
011 = Primary oscillator (XT, HS, EC) with PLL
010 = Primary oscillator (XT, HS, EC)
001 = Fast RC oscillator (FRC) with PLL
000 = Fast RC oscillator (FRC)
110 = Fast RC oscillator (FRC) with Divide-by-16
101 = Low-Power RC oscillator (LPRC)
100 = Secondary oscillator (Sosc)
011 = Primary oscillator (XT, HS, EC) with PLL
010 = Primary oscillator (XT, HS, EC)
001 = Fast RC oscillator (FRC) with PLL
000 = Fast RC oscillator (FRC)
bit 7
CLKLOCK: Clock Lock Enable bit
If clock switching is enabled and FSCM is disabled (FOSC<FCKSM> = 0b01)
1 = Clock switching is disabled, system clock source is locked
0 = Clock switching is enabled, system clock source can be modified by clock switching
If clock switching is enabled and FSCM is disabled (FOSC<FCKSM> = 0b01)
1 = Clock switching is disabled, system clock source is locked
0 = Clock switching is enabled, system clock source can be modified by clock switching
bit 6
IOLOCK: Peripheral Pin Select Lock bit
1 = Peripherial Pin Select is locked, write to Peripheral Pin Select register is not allowed
0 = Peripherial Pin Select is unlocked, write to Peripheral Pin Select register is allowed
1 = Peripherial Pin Select is locked, write to Peripheral Pin Select register is not allowed
0 = Peripherial Pin Select is unlocked, write to Peripheral Pin Select register is allowed
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
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’
Note 1: Writes to this register require an unlock sequence. Refer to Section 7. “Oscillator” (DS70186) in the
“dsPIC33F/PIC24H Family Reference Manual” for details.
2: 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.
mode as a transition clock source between the two PLL modes.
3: This register is reset only on a Power-on Reset (POR).