PIC16F870_13 Datasheet, PDF (129/172 Pages) Microchip Technology – 28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

PIC16F870/871
FIGURE 14-6:
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
I/O Pins
33
32
30
31
34
34
Note: Refer to Figure 14-3 for load conditions.
FIGURE 14-7:
BROWN-OUT RESET TIMING
VDD
VBOR
35
TABLE 14-3: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER,
AND BROWN-OUT RESET REQUIREMENTS
Param
No.
Sym
Characteristic
Min
Typ†
Max Units
Conditions
30
TmcL MCLR Pulse Width (low)
2
—
—
s VDD = 5V, -40°C to +85°C
31*
TWDT Watchdog Timer Time-out Period
7
(No Prescaler)
18
33
ms VDD = 5V, -40°C to +85°C
32
TOST
Oscillation Start-up Timer Period
— 1024 TOSC —
— TOSC = OSC1 period
33*
TPWRT Power up Timer Period
28
72
132 ms VDD = 5V, -40°C to +85°C
34
TIOZ
I/O Hi-impedance from MCLR Low or —
—
2.1
s
Watchdog Timer Reset
35
TBOR Brown-out Reset pulse width
100
—
—
s 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.
 2000-2013 Microchip Technology Inc.
DS30569C-page 129