PIC18F23K20-E/MLQTP MICROCHIP [Microchip Technology], PIC18F23K20-E/MLQTP Datasheet - Page 58

• Manufacturer Part Number: PIC18F23K20-E/MLQTP
• Description: 28/40/44-Pin Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2XK20/4XK20
4.6
Some registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. All other registers are forced to a “Reset state”
depending on the type of Reset that occurred.
Most registers are not affected by a WDT wake-up,
since this is viewed as the resumption of normal
operation. Status bits from the RCON register, RI, TO,
PD, POR and BOR, are set or cleared differently in
different Reset situations, as indicated in Table 4-3.
These bits are used by software to determine the
nature of the Reset.
TABLE 4-3:
DS41303B-page 56
Power-on Reset
RESET Instruction
Brown-out Reset
MCLR during Power-Managed
Run Modes
MCLR during Power-Managed
Idle Modes and Sleep Mode
WDT Time-out during Full Power
or Power-Managed Run Mode
MCLR during Full Power
Execution
Stack Full Reset (STVREN = 1)
Stack Underflow Reset
(STVREN = 1)
Stack Underflow Error (not an
actual Reset, STVREN = 0)
WDT Time-out during
Power-Managed Idle or Sleep
Modes
Interrupt Exit from
Power-Managed Modes
Legend: u = unchanged
Note 1:
2:
Reset State of Registers
When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the
interrupt vector (008h or 0018h).
Reset state is ‘1’ for POR and unchanged for all other Resets when software BOR is enabled
(BOREN<1:0> Configuration bits = 01 and SBOREN = 1). Otherwise, the Reset state is ‘0’.
Condition
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION
FOR RCON REGISTER
Program
PC + 2
Counter
PC + 2
0000h
0000h
0000h
0000h
0000h
0000h
0000h
0000h
0000h
0000h
(1)
Advance Information
SBOREN
u
u
u
u
u
u
u
u
u
u
u
1
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
RCON Register
RI
Table 4-4 describes the Reset states for all of the
Special Function Registers. These are categorized by
Power-on and Brown-out Resets, Master Clear and
WDT Resets and WDT wake-ups.
1
0
1
u
u
u
u
u
u
u
u
u
TO
1
u
1
1
1
0
u
u
u
u
0
u
PD
1
u
1
u
0
u
u
u
u
u
0
0
POR BOR STKFUL
0
u
u
u
u
u
u
u
u
u
u
u
© 2007 Microchip Technology Inc.
0
u
0
u
u
u
u
u
u
u
u
u
STKPTR Register
0
u
u
u
u
u
u
1
u
u
u
u
STKUNF
0
u
u
u
u
u
u
u
1
1
u
u