PIC18F2220/2320/4220/4320
REGISTER 23-1: CONFIG1H:CONFIGURATIONREGISTER1HIGH(BYTEADDRESS300001h)
R/P-1
IESO
R/P-1
U-0
—
U-0
—
R/P-1
R/P-1
R/P-1
R/P-1
FSCM
FOSC3
FOSC2
FOSC1
FOSC0
bit 7
bit 0
bit 7
bit 6
IESO: Internal External Switch Over bit
1= Internal External Switch Over mode enabled
0= Internal External Switch Over mode disabled
FSCM: 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 FOSC<3:0>: Oscillator Selection bits
11xx= External RC oscillator, CLKO function on RA6
1001= Internal oscillator block, CLKO function on RA6 and port function on RA7
1000= Internal oscillator block, port function on RA6 and port function on 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
0010= HS oscillator
0001= XT oscillator
0000= LP oscillator
Legend:
R = Readable bit
P = Programmable bit U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
- n = Value when device is unprogrammed
DS39599C-page 238
2003 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
