Datasheet

 2001-2013 Microchip Technology Inc. DS39598F-page 93
PIC16F818/819
12.9 Power Control/Status Register
(PCON)
The Power Control/Status register, PCON, has two bits
to indicate the type of Reset that last occurred.
Bit 0 is Brown-out Reset Status bit, BOR. Bit BOR is
unknown on a Power-on Reset. It must then be set by
the user and checked on subsequent Resets to see if
bit BOR
cleared, indicating a Brown-out Reset
occurred. When the Brown-out Reset is disabled, the
state of the BOR bit is unpredictable.
Bit 1 is Power-on Reset Status bit, POR
. It is cleared on
a Power-on Reset and unaffected otherwise. The user
must set this bit following a Power-on Reset.
TABLE 12-1: TIME-OUT IN VARIOUS SITUATIONS
TABLE 12-2: STATUS BITS AND THEIR SIGNIFICANCE
TABLE 12-3: RESET CONDITION FOR SPECIAL REGISTERS
Oscillator
Configuration
Power-up Brown-out Reset
Wake-up
from Sleep
PWRTE
= 0 PWRTE = 1 PWRTE = 0 PWRTE = 1
XT, HS, LP T
PWRT + 1024 • TOSC 1024 • TOSC TPWRT + 1024 • TOSC 1024 • TOSC 1024 • TOSC
EXTRC, EXTCLK, INTRC TPWRT 5-10 s
(1)
TPWRT 5-10 s
(1)
5-10 s
(1)
Note 1: CPU start-up is always invoked on POR, BOR and wake-up from Sleep.
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: u = unchanged, x = unknown
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).