PIC16F7X Datasheet, PDF (97/174 Pages) Microchip Technology – 28/40-Pin 8-Bit CMOS FLASH Microcontrollers

PIC16F7X
12.10 Power Control/Status Register
(PCON)
The Power Control/Status Register, PCON, has two
bits to indicate the type of RESET that last occurred.
Bit0 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.
Bit1 is POR (Power-on Reset Status bit). It is cleared on
a Power-on Reset and unaffected otherwise. The user
must set this bit following a Power-on Reset.
TABLE 12-3: TIME-OUT IN VARIOUS SITUATIONS
Oscillator Configuration
XT, HS, LP
RC
Power-up
PWRTE = 0
72 ms + 1024 TOSC
72 ms
PWRTE = 1
1024 TOSC
—
Brown-out
72 ms + 1024 TOSC
72 ms
Wake-up from
SLEEP
1024 TOSC
—
TABLE 12-4: STATUS BITS AND THEIR SIGNIFICANCE
POR
BOR
TO
PD
(PCON<1>) (PCON<0>) (STATUS<4>) (STATUS<3>)
Significance
0
x
1
0
x
0
0
x
x
1
0
1
1
1
0
1
1
0
1
1
u
1
1
1
1
Power-on Reset
x
Illegal, TO is set on POR
0
Illegal, PD is set on POR
1
Brown-out Reset
1
WDT Reset
0
WDT Wake-up
u
MCLR Reset during normal operation
0
MCLR Reset during SLEEP or interrupt wake-up from
SLEEP
TABLE 12-5: RESET CONDITION FOR SPECIAL REGISTERS
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).
 2002 Microchip Technology Inc.
DS30325B-page 95