PIC16F87XA
DS39582B-page 184
2003 Microchip Technology Inc.
FIGURE 17-6:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
FIGURE 17-7:
BROWN-OUT RESET TIMING
TABLE 17-5:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
V
DD
MCLR
Internal
POR
PWRT
Time-out
OSC
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
30
31
34
I/O pins
34
Note: Refer to Figure 17-3 for load conditions.
V
DD
V
BOR
35
Param
No.
Symbol
Characteristic
Min
Typ†
Max
Units
Conditions
30
T
MC
L
MCLR Pulse Width (low)
2
—
—
µ
s
V
DD
= 5V, -40°C to +85°C
31*
T
WDT
Watchdog Timer Time-out Period
(no prescaler)
7
18
33
ms
V
DD
= 5V, -40°C to +85°C
32
T
OST
Oscillation Start-up Timer Period
—
1024 T
OSC
—
—
T
OSC
= OSC1 period
33*
T
PWRT
Power-up Timer Period
28
72
132
ms
V
DD
= 5V, -40°C to +85°C
34
T
IOZ
I/O High-Impedance from MCLR Low
or Watchdog Timer Reset
—
—
2.1
µ
s
35
T
BOR
Brown-out Reset Pulse Width
100
—
—
µ
s
V
DD
≤
V
BOR
(D005)
*
These parameters are characterized but not tested.
†
Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
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