PIC16F87_05 Datasheet, PDF (183/228 Pages) Microchip Technology – 18/20/28-Pin Enhanced Flash Microcontrollers with nanoWatt Technology

PIC16F87/88
FIGURE 18-6:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
VDD
MCLR
Internal
POR
PWRT
Time-out
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
I/O Pins
33
32
30
31
34
34
Note: Refer to Figure 18-3 for load conditions.
FIGURE 18-7:
BROWN-OUT RESET TIMING
VDD
VBOR
35
TABLE 18-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Parameter
No.
Sym
Characteristic
Min
Typ†
Max Units
Conditions
30
TmcL MCLR Pulse Width (Low)
2
—
—
µs VDD = 5V, -40°C to +85°C
31*
TWDT Watchdog Timer Time-out Period 13.6
16
18.4 ms VDD = 5V, -40°C to +85°C
(16-bit prescaler = 0100 and no
postscaler)
32
TOST
Oscillation Start-up Timer Period
— 1024 TOSC —
— TOSC = OSC1 period
33*
TPWRT Power-up Timer Period
61.2
72
82.8 ms VDD = 5V, -40°C to +85°C
34
TIOZ
I/O High-impedance from MCLR
—
—
2.1
µs
Low or Watchdog Timer Reset
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.
 2005 Microchip Technology Inc.
DS30487C-page 181