PIC18F6390_07 Datasheet, PDF (374/414 Pages) Microchip Technology – 64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology

PIC18F6390/6490/8390/8490
FIGURE 26-7:
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
33
32
I/O pins
Note: Refer to Figure 26-4 for load conditions.
30
34
31
34
FIGURE 26-8:
BROWN-OUT RESET TIMING
VDD
VIRVST
BVDD
35
Enable Internal
Reference Voltage
Internal Reference
Voltage Stable
36
VBGAP = 1.2V
TABLE 26-10: 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)
2
—
—
μs
31
TWDT Watchdog Timer Time-out Period
3.4
4.0
4.6
ms
(No postscaler)
32
TOST Oscillator Start-up Timer Period 1024 TOSC — 1024 TOSC — TOSC = OSC1 period
33
TPWRT Power-up Timer Period
55.5 65.5
75
ms
34
TIOZ I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
—
2
—
μs
35
TBOR Brown-out Reset Pulse Width
200
—
—
μs VDD ≤ BVDD (see D005)
36
TIRVST Time for Internal Reference
Voltage to become Stable
—
20
50
μs
37
TLVD Low-Voltage Detect Pulse Width
200
—
—
μs VDD ≤ VLVD
38
TCSD CPU Start-up Time
—
10
—
μs
39
TIOBST Time for INTRC Block to Stabilize
—
1
—
ms
DS39629C-page 372
© 2007 Microchip Technology Inc.