PIC18F2510-ESLASHML datasheet(41/376 Pages) MICROCHIP

41 / 376 page

DS39636D-page 43

PIC18F2X1X/4X1X

4.0

RESET

The PIC18F2X1X/4X1X devices differentiate between

various kinds of Reset:

Power-on Reset (POR)

MCLR Reset during normal operation

MCLR Reset during power-managed modes

Watchdog Timer (WDT) Reset (during

execution)

Programmable Brown-out Reset (BOR)

RESET Instruction

Stack Full Reset

Stack Underflow Reset

This section discusses Resets generated by MCLR,

POR and BOR and covers the operation of the various

start-up timers. Stack Reset events are covered in

Section 5.1.2.4 “Stack Full and Underflow Resets”.

WDT Resets are covered in Section 22.2 “Watchdog

Timer (WDT)”.

A simplified block diagram of the On-Chip Reset Circuit

is shown in Figure 4-1.

4.1

RCON Register

Device Reset events are tracked through the RCON

occurred. In most cases, these bits can only be cleared

by the event and must be set by the application after

the event. The state of these flag bits, taken together,

can be read to indicate the type of Reset that just

occurred. This is described in more detail in

Section 4.6 “Reset State of Registers”.

The RCON register also has control bits for setting

interrupt priority (IPEN) and software control of the

BOR (SBOREN). Interrupt priority is discussed in

Section 8.0 “Interrupts”.

BOR

is covered

Section 4.4 “Brown-out Reset (BOR)”.

FIGURE 4-1:

SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External Reset

MCLR

VDD

OSC1

WDT

Time-out

VDD Rise

Detect

OST/PWRT

INTRC(1)

POR Pulse

OST

10-bit Ripple Counter

PWRT

11-bit Ripple Counter

Enable OST(2)

Enable PWRT

Note 1: This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin.

2: See Table 4-2 for time-out situations.

Brown-out

Reset

BOREN

RESET

Instruction

Stack

Pointer

Stack Full/Underflow Reset

Sleep

( )_IDLE

1024 Cycles

65.5 ms

μs

MCLRE

Chip_Reset

PIC18F2510-E/ML 数据表(PDF) 41 Page - Microchip Technology

PIC18F2510-E/ML 数据表(HTML) 41 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载