PIC18F2220 Datasheet, PDF (330/388 Pages) Microchip Technology – 28/40/44-Pin High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology

PIC18F2220/2320/4220/4320
FIGURE 26-8:
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 26-5 for load conditions.
30
34
31
34
FIGURE 26-9:
BROWN-OUT RESET TIMING
VDD
BVDD
35
VIRVST
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 (no postscaler) 3.48 4.00 4.71
ms
32
TOST Oscillation Start-up Timer Period
1024 TOSC — 1024 TOSC — TOSC = OSC1 period
33
TPWRT Power-up Timer Period
57.0 65.5 77.2
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
TIVRST Time for Internal Reference Voltage to become
—
20
50
µs
stable
37
TLVD Low-Voltage Detect Pulse Width
200
—
—
µs VDD ≤ VLVD
DS39599C-page 328
 2003 Microchip Technology Inc.