
PIC18F1230/1330
DS39758D-page 192
2009 Microchip Technology Inc.
REGISTER 20-1:
CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
R/P-0
U-0
R/P-0
R/P-1
IESO
FCMEN
—
FOSC3
FOSC2
FOSC1
FOSC0
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
u = Unchanged from programmed state
bit 7
IESO:
Internal/External Oscillator Switchover bit
1
= Oscillator Switchover mode enabled
0
= Oscillator Switchover mode disabled
bit 6
FCMEN:
Fail-Safe Clock Monitor Enable bit
1
= Fail-Safe Clock Monitor enabled
0
= Fail-Safe Clock Monitor disabled
bit 5-4
Unimplemented:
Read as ‘0’
bit 3-0
FOSC3:FOSC0:
Oscillator Selection bits
11xx
= External RC oscillator, CLKO function on RA6
101x
= External RC oscillator, CLKO function on RA6
1001
= Internal oscillator block, CLKO function on RA6, port function on RA7
1000
= Internal oscillator block, port function on RA6 and RA7
0111
= External RC oscillator, port function on RA6
0110
= HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1)
0101
= EC oscillator, port function on RA6
0100
= EC oscillator, CLKO function on RA6
0011
= External RC oscillator, CLKO function on RA6
0010
= HS oscillator
0001
= XT oscillator
0000
= LP oscillator