PIC16LF877A-I Datasheet, PDF (151/234 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers

PIC16F87XA
14.10 Power Control/Status Register
(PCON)
The Power Control/Status Register, PCON, has up to
two bits depending upon the device.
Bit 0 is the Brown-out Reset Status bit, BOR. The BOR
bit is unknown on a Power-on Reset. It must then be set
by the user and checked on subsequent Resets to see if
it has been cleared, indicating that a BOR has occurred.
When the Brown-out Reset is disabled, the state of the
BOR bit is unpredictable and is, therefore, not valid at
any time.
Bit 1 is the Power-on Reset Status bit, POR. It is
cleared on a Power-on Reset and unaffected other-
wise. The user must set this bit following a Power-on
Reset.
TABLE 14-3: TIME-OUT IN VARIOUS SITUATIONS
Oscillator Configuration
Power-up
PWRTE = 0
PWRTE = 1
XT, HS, LP
RC
72 ms + 1024 TOSC
72 ms
1024 TOSC
—
Brown-out
72 ms + 1024 TOSC
72 ms
Wake-up from
Sleep
1024 TOSC
—
TABLE 14-4: STATUS BITS AND THEIR SIGNIFICANCE
POR BOR TO PD
Condition
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 MCLR Reset during Sleep or Interrupt Wake-up from Sleep
Legend: x = don’t care, u = unchanged
TABLE 14-5: RESET CONDITIONS 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).
 2003 Microchip Technology Inc.
DS39582B-page 149