Datasheet

PIC12F635/PIC16F636/639
DS41232D-page 46 © 2007 Microchip Technology Inc.
FIGURE 3-9: FSCM TIMING DIAGRAM
TABLE 3-2: SUMMARY OF REGISTERS ASSOCIATED WITH CLOCK SOURCES
OSFIF
System
Clock
Output
Sample Clock
Failure
Detected
Oscillator
Failure
Note: The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.
(Q)
Test
Test Test
Clock Monitor Output
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on
POR, BOR
Value on
all other
Resets
(1)
CONFIG
(2)
CPD CP MCLRE PWRTE WDTE FOSC2 FOSC1 FOSC0 — —
INTCON GIE PEIE
T0IE INTE RAIE T0IF INTF RAIF 0000 000x 0000 000x
OSCCON
— IRCF2 IRCF1 IRCF0 OSTS HTS LTS SCS -110 x000 -110 x000
OSCTUNE
— — — TUN4 TUN3 TUN2 TUN1 TUN0 ---0 0000 ---u uuuu
PIE1
EEIE LVDIE CRIE C2IE
(3)
C1IE OSFIE — TMR1IE 000- 00-0 000- 00-0
PIR1
EEIF LVDIF CRIF C2IF
(3)
C1IF OSFIF — TMR1IF 000- 00-0 000- 00-0
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by oscillators.
Note 1: Other (non Power-up) Resets include MCLR
Reset and Watchdog Timer Reset during normal operation.
2: See
Configuration Word register (CONFIG) for operation of all register bits.
3: PIC16F636/639 only.