
2010 Microchip Technology Inc.
DS41303G-page 29
PIC18F2XK20/4XK20
REGISTER 2-1:
OSCCON: OSCILLATOR CONTROL REGISTER
R/W-0
R/W-1
R-q
R-0
R/W-0
IDLEN
IRCF2
IRCF1
IRCF0
OSTS(1)
IOFS
SCS1
SCS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
q = depends on condition
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
IDLEN: Idle Enable bit
1
= Device enters Idle mode on SLEEP instruction
0
= Device enters Sleep mode on SLEEP instruction
bit 6-4
IRCF<2:0>: Internal Oscillator Frequency Select bits
111
= 16 MHz (HFINTOSC drives clock directly)
110
= 8 MHz
101
= 4 MHz
100
= 2 MHz
011
= 1 MHz(3)
010
= 500 kHz
001
= 250 kHz
000
= 31 kHz (from either HFINTOSC/512 or LFINTOSC directly)(2)
bit 3
OSTS: Oscillator Start-up Time-out Status bit(1)
1
= Device is running from the clock defined by FOSC<2:0> of the CONFIG1 register
0
= Device is running from the internal oscillator (HFINTOSC or LFINTOSC)
bit 2
IOFS: HFINTOSC Frequency Stable bit
1
= HFINTOSC frequency is stable
0
= HFINTOSC frequency is not stable
bit 1-0
SCS<1:0>: System Clock Select bits
1x
= Internal oscillator block
01
= Secondary (Timer1) oscillator
00
= Primary clock (determined by CONFIG1H[FOSC<3:0>]).
Note 1:
Reset state depends on state of the IESO Configuration bit.
2:
Source selected by the INTSRC bit of the OSCTUNE register, see text.
3:
Default output frequency of HFINTOSC on Reset.