
PIC18FXX39
DS30485A-page 272
Preliminary
2002 Microchip Technology Inc.
FIGURE 23-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
FIGURE 23-8:
BROWN-OUT RESET TIMING
TABLE 23-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
30
TmcL
MCLR Pulse Width (low)
2
—
s
31
TWDT
Watchdog Timer Time-out Period (No
Postscaler)
718
33
ms
32
TOST
Oscillation Start-up Timer Period
1024 TOSC
—
1024 TOSC
—TOSC = OSC1 period
33
TPWRT
Power up Timer Period
28
72
132
ms
34
TIOZ
I/O high impedance from MCLR Low
or Watchdog Timer Reset
—2
—
s
35
TBOR
Brown-out Reset Pulse Width
200
—
sVDD ≤ BVDD (see D005)
36
TIVRST
Time for Internal Reference
Voltage to become stable
—20
500
s
37
TLVD
Low Voltage Detect Pulse Width
200
—
sVDD ≤ VLVD (see D420)
VDD
MCLR
Internal
POR
PWRT
Time-out
OSC
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
30
31
34
I/O Pins
34
Note:
VDD
BVDD
35
VBGAP = 1.2V
VIRVST
Enable Internal Reference Voltage
Internal Reference Voltage stable
36
Typical