PIC18F258-I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18F258-I/SP

28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module

Microchip Technology 

PIC18FXX8

FIGURE 27-8:

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 27-5 for load conditions.

30

31

34

34

FIGURE 27-9:

BROWN-OUT RESET AND LOW-VOLTAGE DETECT TIMING

VDD

VIRVST

BVDD (for 35)

VLVD (for 37)

35, 37

Enable Internal

Reference Voltage

Internal Reference

Voltage Stable

36

VBGAP = 1.2V

TABLE 27-9: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER,

BROWN-OUT RESET AND LOW-VOLTAGE DETECT 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 prescaler)

7

18

33

ms

32

TOST

Oscillation Start-up Timer Period

1024 TOSC — 1024 TOSC — TOSC = OSC1 period

33

TPWRT Power-up Timer Period

28

72

132

ms

34

TIOZ

I/O High-Impedance from MCLR Low

—

2

—

μs

or Watchdog Timer Reset

35

TBOR Brown-out Reset Pulse Width

200

—

—

μs For 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 For VDD ≤ VLVD (see D420)

© 2006 Microchip Technology Inc.

DS41159E-page 345

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