PIC16LF819-I Datasheet, PDF (95/176 Pages) Microchip Technology – Enhanced Flash Microcontrollers with nanoWatt Technology

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
Oscillator
Configuration
Power-up
PWRTE = 0
PWRTE = 1
Brown-out Reset
PWRTE = 0
PWRTE = 1
XT, HS, LP
TPWRT + 1024 • TOSC 1024 • TOSC TPWRT + 1024 • TOSC 1024 • TOSC
EXTRC, EXTCLK, INTRC
TPWRT
5-10 µs⁽¹⁾
TPWRT
5-10 µs⁽¹⁾
Note 1: CPU start-up is always invoked on POR, BOR and wake-up from Sleep.
Wake-up
from Sleep
1024 • TOSC
5-10 µs⁽¹⁾
TABLE 12-2: STATUS BITS AND THEIR SIGNIFICANCE
POR
BOR
TO
PD
0
x
1
1
Power-on Reset
0
x
0
x
Illegal, TO is set on POR
0
x
x
0
Illegal, PD is set on POR
1
0
1
1
Brown-out Reset
1
1
0
1
WDT Reset
1
1
0
0
WDT wake-up
1
1
u
u
MCLR Reset during normal operation
1
1
1
0
Legend: u = unchanged, x = unknown
MCLR Reset during Sleep or interrupt wake-up from Sleep
TABLE 12-3: 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
Interrupt wake-up from Sleep
000h
PC + 1⁽¹⁾
0001 1uuu
uuu1 0uuu
---- --u0
---- --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).
 2004 Microchip Technology Inc.
DS39598E-page 93