PIC18F2680ISPSQTP datasheet(43/482 Pages) MICROCHIP

43 / 482 page

Preliminary

DS39625C-page 41

PIC18F2585/2680/4585/4680

4.0

RESET

The PIC18F2585/2680/4585/4680 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 24.2 “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

described

detail

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 9.0

“Interrupts”.

BOR

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

Chip_Reset

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.

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

PIC18F2680ISPSQTP bảng dữ liệu(PDF) 43 Page - Microchip Technology

PIC18F2680ISPSQTP bảng dữ liệu(HTML) 43 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

bảng dữ liệu tải về

Link URL