PIC16F87XA Datasheet, PDF (186/234 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers

PIC16F87XA
FIGURE 17-6:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
VDD
MCLR
Internal
POR
PWRT
Time-out
OSC
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
I/O pins
Note: Refer to Figure 17-3 for load conditions.
30
31
34
34
FIGURE 17-7:
BROWN-OUT RESET TIMING
VDD
VBOR
35
TABLE 17-5: 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)
31*
TWDT Watchdog Timer Time-out Period
(no prescaler)
2
—
—
µs VDD = 5V, -40°C to +85°C
7
18
33
ms VDD = 5V, -40°C to +85°C
32
TOST
Oscillation Start-up Timer Period
33*
TPWRT Power-up Timer Period
— 1024 TOSC —
— TOSC = OSC1 period
28
72
132 ms VDD = 5V, -40°C to +85°C
34
TIOZ
I/O High-Impedance from MCLR Low —
or Watchdog Timer Reset
—
2.1
µs
35
TBOR Brown-out Reset Pulse Width
100
—
—
µs VDD ≤ VBOR (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.
DS39582B-page 184
 2003 Microchip Technology Inc.