Datasheet

PIC16F526
DS41326E-page 48  2010 Microchip Technology Inc.
8.3 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 on pin 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 on
pin change Reset during normal operation. They are
not affected by a WDT Reset during Sleep or MCLR
Reset during Sleep, since these Resets are viewed as
resumption of normal operation. The exceptions to this
are TO, PD and RBWUF 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 8-3 for a full description of Reset states of all
registers.
TABLE 8-3: RESET CONDITIONS FOR REGISTERS
Register Address Power-on Reset
MCLR
Reset, WDT Time-out,
Wake-up On Pin Change
W — qqqq qqq0
(1)
qqqq qqq0
(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 100x xxxx 1uuu uuuu
OSCCAL 05h 1111 111- uuuu uuu-
PORTB 06h --xx xxxx --uu uuuu
PORTC 07h --xx xxxx --uu uuuu
CMICON0 08h q111 1111 quuu uuuu
ADCON0 09h 1111 1100 1111 1100
ADRES 0Ah xxxx xxxx uuuu uuuu
CM2CON0 0Bh q111 1111 quuu uuuu
VRCON 0Ch 001-1111 uuu-uuuu
OPTION — 1111 1111 1111 1111
TRISB — --11 1111 --11 1111
TRISC — --11 1111 --11 1111
EECON 21h/61h ---0 x000 ---0 q000
EEDATA 25h/65h xxxx xxxx uuuu uuuu
EEADR 26h/66h --xx xxxx --uu uuuu
Legend: u = unchanged, x = unknown, – = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: Bits <7:1> of W register contain oscillator calibration values due to MOVLW XX instruction at top of
memory.
2: See Table 8-4 for Reset value for specific conditions.