Datasheet

PIC18F87K90 FAMILY
DS39957D-page 428  2009-2011 Microchip Technology Inc.
REGISTER 28-2: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
R/P-0 R/P-0 U-0 U-0 R/P-1 R/P-0 R/P-0 R/P-0
IESO FCMEN
—PLLCFG
(1)
FOSC3
(2)
FOSC2
(2)
FOSC1
(2)
FOSC0
(2)
bit 7 bit 0
Legend: P = Programmable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7
IESO: Internal/External Oscillator Switchover bit
1 = Two-Speed Start-up is enabled
0 = Two-Speed Start-up is disabled
bit 6
FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor is enabled
0 = Fail-Safe Clock Monitor is disabled
bit 5
Unimplemented: Read as ‘0’
bit 4
PLLCFG: 4x PLL Enable bit
(1)
1 = Oscillator is multiplied by 4
0 = Oscillator is used directly
bit 3-0
FOSC<3:0>: Oscillator Selection bits
(2)
1101 = EC1, EC oscillator (low power, DC-160 kHz)
1100 = EC1IO, EC oscillator with CLKOUT function on RA6 (low power, DC-160 kHz)
1011 = EC2, EC oscillator (medium power, 160 kHz-16 MHz)
1010 = EC2IO, EC oscillator with CLKOUT function on RA6 (medium power,160 kHz-16MHz)
0101 = EC3, EC oscillator (high power, 4 MHz-64 MHz)
0100 = EC3IO, EC oscillator with CLKOUT function on RA6 (high power, 4 MHz-64 MHz)
0011 = HS1, HS oscillator (medium power, 4 MHz-16 MHz)
0010 = HS2, HS oscillator (high power, 16 MHz-25 MHz)
0001 = XT oscillator
0000 = LP oscillator
0111 = RC, External RC oscillator
0110 = RCIO, External RC oscillator with CKLOUT function on RA6
1000 = INTIO2, Internal RC oscillator
1001 = INTIO1, Internal RC oscillator with CLKOUT function on RA6
Note 1: Not valid for the INTIOx PLL mode.
2: INTIO+PLL can only be enabled by the PLLEN bit (OSCTUNE<6>). Other PLL modes can be enabled by
either the PLLEN bit or the PLLCFG (CONFIG1H<4>) bit.