PIC18F67J11T-I Datasheet, PDF (38/466 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Flash Microcontrollers

PIC18F87J11 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 3-2) controls the
tuning and operation of the internal oscillator block. It
also implements the PLLEN bits which control the
operation of the Phase Locked Loop (PLL) (see
Section 3.4.3 “PLL Frequency Multiplier”).
REGISTER 3-1: OSCCON: OSCILLATOR CONTROL REGISTER⁽¹⁾
R/W-0
R/W-1
R/W-1
R/W-0
R⁽²⁾
U-1
IDLEN
IRCF2⁽³⁾
IRCF1⁽³⁾
IRCF0⁽³⁾
OSTS
—
bit 7
R/W-0
SCS1⁽⁵⁾
R/W-0
SCS0⁽⁵⁾
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
bit 2
bit 1-0
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>: INTOSC Source Frequency Select bits⁽³⁾
111 = 8 MHz (INTOSC drives clock directly)
110 = 4 MHz (default)
101 = 2 MHz
100 = 1 MHz
011 = 500 kHz
010 = 250 kHz
001 = 125 kHz
000 = 31 kHz (from either INTOSC/256 or INTRC)⁽⁴⁾
OSTS: Oscillator Start-up Timer Time-out Status bit⁽²⁾
1 = Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running
0 = Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready
Unimplemented: Read as ‘1’
SCS<1:0>: System Clock Select bits⁽⁵⁾
11 = Internal oscillator block
10 = Primary oscillator
01 = Timer1 oscillator
00 = Default primary oscillator (as defined by the FOSC<2:0> Configuration bits)
Note 1:
2:
3:
4:
5:
Default (legacy) SFR at this address, available when WDTCON<4> = 0.
Reset state depends on the state of the IESO Configuration bit.
Modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing
the device clocks.
The source is selected by the INTSRC bit (OSCTUNE<7>), see text.
Modifying these bits will cause an immediate clock source switch.
DS39778E-page 38
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