Datasheet

© 2007 Microchip Technology Inc. DS41268D-page 61
PIC12F510/16F506
10.3 Reset
The device differentiates between various kinds of
Reset:
• Power-on Reset (POR)
•MCLR
Reset during normal operation
•MCLR
Reset during Sleep
• WDT Time-out Reset during normal operation
• WDT Time-out Reset during Sleep
• Wake-up from Sleep Reset on pin change
• Wake-up from Sleep Reset on comparator
change
Some registers are not reset in any way, they are
unknown on POR and unchanged in any other Reset.
Most other registers are reset to “Reset state” on
Power-on Reset (POR), MCLR
, WDT or Wake-up from
Sleep Reset on pin change or wake-up from Sleep
Reset on comparator change. The exceptions are TO,
PD
, CWUF and RBWUF/GPWUF bits. They are set or
cleared differently in different Reset situations. These
bits are used in software to determine the nature of
Reset. See Table 10-4 for a full description of Reset
states of all registers.
TABLE 10-3: RESET CONDITIONS FOR REGISTERS – PIC12F510
Register Address Power-on Reset
MCLR
Reset, WDT Time-out,
Wake-up On Pin Change, Wake-up on
Comparator Change
W—qqqq qqqu
(1)
qqqq qqqu
(1)
INDF 00h xxxx xxxx uuuu uuuu
TMR0 01h xxxx xxxx uuuu uuuu
PCL 02h 1111 1111 1111 1111
STATUS 03h 0001 1xxx qq0q quuu
(2)
FSR 04h 110x xxxx 11uu uuuu
OSCCAL 05h 1111 111- uuuu uuu-
GPIO 06h --xx xxxx --uu uuuu
CM1CON0 07h 1111 1111 uuuu uuuu
ADCON0 08h 1111 1100 uu11 1100
ADRES 09h xxxx xxxx uuuu uuuu
OPTION — 1111 1111 1111 1111
TRISIO — --11 1111 --11 1111
Legend: u = unchanged, x = unknown, – = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: Bits <7:2> of W register contain oscillator calibration values due to MOVLW XX instruction at top of
memory.
2: See Table 10-5 for Reset value for specific conditions.