Datasheet
2000-2013 Microchip Technology Inc. DS30569C-page 93
PIC16F870/871
TABLE 11-4: STATUS BITS AND THEIR SIGNIFICANCE
TABLE 11-5: RESET CONDITION FOR SPECIAL REGISTERS
POR BOR TO PD
0x11Power-on Reset
0x0xIllegal, TO is set on POR
0xx0Illegal, PD is set on POR
1011Brown-out Reset
1101WDT Reset
1100WDT Wake-up
11uuMCLR
Reset during normal operation
1110MCLR Reset during SLEEP or interrupt wake-up from SLEEP
Legend: x = don’t care, u = unchanged
Condition
Program
Counter
STATUS
Register
PCON
Register
Power-on Reset 000h 0001 1xxx ---- --0x
MCLR
Reset during normal operation 000h 000u uuuu ---- --uu
MCLR
Reset during SLEEP 000h 0001 0uuu ---- --uu
WDT Reset 000h 0000 1uuu ---- --uu
WDT Wake-up PC + 1 uuu0 0uuu ---- --uu
Brown-out Reset 000h 0001 1uuu ---- --u0
Interrupt wake-up from SLEEP PC + 1
(1)
uuu1 0uuu ---- --uu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0'
Note 1: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h).
TABLE 11-6: INITIALIZATION CONDITIONS FOR ALL REGISTERS
Register Devices
Power-on Reset,
Brown-out Reset
MCLR
Resets
WDT Reset
Wake-up via WDT or
Interrupt
W PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
INDF PIC16F870 PIC16F871 N/A N/A N/A
TMR0 PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
PCL PIC16F870 PIC16F871 0000h 0000h PC + 1
(2)
STATUS PIC16F870 PIC16F871 0001 1xxx 000q quuu
(3)
uuuq quuu
(3)
FSR PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
PORTA PIC16F870 PIC16F871 --0x 0000 --0u 0000 --uu uuuu
PORTB PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
PORTC PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
PORTD
PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu
PORTE
PIC16F870 PIC16F871 ---- -xxx ---- -uuu ---- -uuu
PCLATH PIC16F870 PIC16F871 ---0 0000 ---0 0000 ---u uuuu
INTCON PIC16F870 PIC16F871 0000 000x 0000 000u uuuu uuuu
(1)
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition,
r = reserved, maintain clear
Note 1: One or more bits in INTCON, PIR1 and/or PIR2 will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector
(0004h).
3: See Table 11-5 for RESET value for specific condition.