PIC16F876ATISLASHML datasheet(149/234 Pages) MICROCHIP

149 / 234 page

 2003 Microchip Technology Inc.

DS39582B-page 147

PIC16F87XA

14.3

Reset

The PIC16F87XA differentiates between various kinds

of Reset:

• Power-on Reset (POR)

•MCLR Reset during normal operation

•MCLR Reset during Sleep

• WDT Reset (during normal operation)

• WDT Wake-up (during Sleep)

• Brown-out Reset (BOR)

Some registers are not affected in any Reset condition.

Their status is unknown on POR and unchanged in any

other Reset. Most other registers are reset to a “Reset

state” on Power-on Reset (POR), on the MCLR and

WDT Reset, on MCLR Reset during Sleep and Brown-

out Reset (BOR). They are not affected by a WDT

wake-up which is viewed as the resumption of normal

operation. The TO and PD bits are set or cleared differ-

ently in different Reset situations as indicated in

Table 14-4. These bits are used in software to deter-

mine the nature of the Reset. See Table 14-6 for a full

description of Reset states of all registers.

A simplified block diagram of the on-chip Reset circuit

is shown in Figure 14-4.

FIGURE 14-4:

SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External

Reset

MCLR

VDD

OSC1

WDT

Module

VDD Rise

Detect

OST/PWRT

On-chip

RC OSC

WDT

Time-out

Power-on Reset

OST

10-bit Ripple Counter

PWRT

Chip_Reset

10-bit Ripple Counter

Reset

Enable OST

Enable PWRT

Sleep

Note 1:

This is a separate oscillator from the RC oscillator of the CLKI pin.

Brown-out

Reset

BODEN

(1)

PIC16F876ATI/ML Datasheet(PDF) 149 Page - Microchip Technology

PIC16F876ATI/ML Datasheet(HTML) 149 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

Datasheet Download

Link URL