PIC18F87K22 Datasheet, PDF (43/548 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Enhanced Flash Microcontrollers with 12-Bit A/D and nanoWatt XLP Technology

PIC18F87K22 FAMILY
3.2 Control Registers
The OSCCON register (Register 3-1) controls the main
aspects of the device clock’s operation. It selects the
oscillator type to be used, which of the power-managed
modes to invoke and the output frequency of the
INTOSC source. It also provides status on the oscillators.
The OSCTUNE register (Register 3-3) controls the
tuning and operation of the internal oscillator block. It also
implements the PLLEN bit which controls the operation of
the Phase Locked Loop (PLL) (see Section 3.5.3 “PLL
Frequency Multiplier”).
REGISTER 3-1: OSCCON: OSCILLATOR CONTROL REGISTER⁽¹⁾
R/W-0
IDLEN
bit 7
R/W-1
IRCF2⁽²⁾
R/W-1
IRCF1⁽²⁾
R/W-0
IRCF0⁽²⁾
R⁽¹⁾
OSTS
R-0
HFIOFS
R/W-0
SCS1⁽⁴⁾
R/W-0
SCS0⁽⁴⁾
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6-4
bit 3
IDLEN: Idle Enable bit
1 = Device enters an Idle mode when a SLEEP instruction is executed
0 = Device enters Sleep mode when a SLEEP instruction is executed
IRCF<2:0>: Internal Oscillator Frequency Select bits⁽²⁾
111 = HF-INTOSC output frequency used (16 MHz)
110 = HF-INTOSC/2 output frequency used (8 MHz, default)
101 = HF-INTOSC/4 output frequency used (4 MHz)
100 = HF-INTOSC/8 output frequency used (2 MHz)
011 = HF-INTOSC/16 output frequency used (1 MHz)
If INTSRC = 0 and MFIOSEL = 0:^(3,5)
010 = HF-INTOSC/32 output frequency used (500 kHz)
001 = HF-INTOSC/64 output frequency used (250 kHz)
000 = LF-INTOSC output frequency used (31.25 kHz)
If INTSRC = 1 and MFIOSEL = 0:^(3,5)
010 = HF-INTOSC/32 output frequency used (500 kHz)
001 = HF-INTOSC/64 output frequency used (250 kHz)
000 = HF-INTOSC/512 output frequency used (31.25 kHz)
If INTSRC = 0 and MFIOSEL = 1:^(3,5)
010 = MF-INTOSC output frequency used (500 kHz)
001 = MF-INTOSC/2 output frequency used (250 kHz)
000 = LF-INTOSC output frequency used (31.25 kHz)⁽⁶⁾
If INTSRC = 1 and MFIOSEL = 1:^(3,5)
010 = MF-INTOSC output frequency used (500 kHz)
001 = MF-INTOSC/2 output frequency used (250 kHz)
000 = MF-INTOSC/16 output frequency used (31.25 kHz)
OSTS: Oscillator Start-up Timer Time-out Status bit⁽¹⁾
1 = Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running, as defined by
FOSC<3:0>
0 = Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready – device is
running from internal oscillator (HF-INTOSC, MF-INTOSC or LF-INTOSC)
Note 1:
2:
3:
4:
5:
6:
The Reset state depends on the state of the IESO Configuration bit (CONFIG1H<7>).
Modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing
the device clocks.
Source selected by the INTSRC bit (OSCTUNE<7>).
Modifying these bits will cause an immediate clock source switch.
INTSRC = OSCTUNE<7> and MFIOSEL = OSCCON2<0>.
Lowest power option for an internal source.
 2010 Microchip Technology Inc.
Preliminary
DS39960B-page 43