PIC18F2331 Datasheet, PDF (360/396 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D

PIC18F2331/2431/4331/4431
FIGURE 25-7:
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 25-4 for load conditions.
30
34
31
34
FIGURE 25-8:
BROWN-OUT RESET TIMING
VDD
BVDD
35
VIRVST
VBGAP = 1.2V
Enable Internal Reference Voltage
Internal Reference Voltage Stable
36
TABLE 25-8: 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 Postscaler)
2
—
—
µs
—
4.00 TBD
ms
32
TOST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC — TOSC = OSC1 period
33
TPWRT Power-up Timer Period
—
65.5 TBD
ms
34
TIOZ I/O Hi-impedance from MCLR Low
—
2
—
or Watchdog Timer Reset
35
TBOR Brown-out Reset Pulse Width
200
—
—
36
TIVRST Time for Internal Reference
—
20
50
Voltage to become stable
37
TLVD Low-Voltage Detect Pulse Width
200
—
—
µs
µs VDD ≤ BVDD (see D005)
µs
µs VDD ≤ VLVD
DS39616B-page 358
Preliminary
 2003 Microchip Technology Inc.