Microchip Technology DM164134 Data Sheet
© 2006 Microchip Technology Inc.
DS41159E-page 345
PIC18FXX8
FIGURE 27-8:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
POWER-UP TIMER TIMING
FIGURE 27-9:
BROWN-OUT RESET AND LOW-VOLTAGE DETECT TIMING
TABLE 27-9:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER,
BROWN-OUT RESET AND LOW-VOLTAGE DETECT REQUIREMENTS
BROWN-OUT RESET AND LOW-VOLTAGE DETECT REQUIREMENTS
Param
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
30
TmcL
MCLR Pulse Width (low)
2
—
—
μs
31
T
WDT
Watchdog Timer Time-out Period
(no prescaler)
(no prescaler)
7
18
33
ms
32
T
OST
Oscillation Start-up Timer Period
1024 T
OSC
—
1024 T
OSC
—
T
OSC
= OSC1 period
33
T
PWRT
Power-up Timer Period
28
72
132
ms
34
T
IOZ
I/O High-Impedance from MCLR Low
or Watchdog Timer Reset
or Watchdog Timer Reset
—
2
—
μs
35
T
BOR
Brown-out Reset Pulse Width
200
—
—
μs
For V
DD
≤ BV
DD
36
T
IRVST
Time for Internal Reference
Voltage to become stable
Voltage to become stable
—
20
50
μs
37
T
LVD
Low-Voltage Detect Pulse Width
200
—
—
μs
For V
DD
≤ V
LVD
(see D420)
V
DD
MCLR
Internal
POR
PWRT
Time-out
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
30
31
34
I/O Pins
34
Note: Refer to Figure 27-5 for load conditions.
V
DD
BV
DD
(for 35)
35, 37
V
BGAP
= 1.2V
V
IRVST
Enable Internal
Internal Reference
36
V
LVD
(for 37)
Reference Voltage
Voltage Stable