PIC16F684 datasheet(101/192 Pages) MICROCHIP

101 / 192 page

DS41202F-page 99

PIC16F684

12.2

Calibration Bits

Brown-out Reset (BOR), Power-on Reset (POR) and

8 MHz internal oscillator (HFINTOSC) are factory cali-

brated. These calibration values are stored in fuses

located in the Calibration Word (2009h). The Calibra-

tion Word is not erased when using the specified bulk

erase sequence in the “PIC12F6XX/16F6XX Memory

Programming Specification” (DS41244) and thus, does

not require reprogramming.

12.3

Reset

The PIC16F684 differentiates between various kinds of

Reset:

Power-on Reset (POR)

WDT Reset during normal operation

WDT Reset during Sleep

MCLR Reset during normal operation

MCLR Reset 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

•MCLR Reset

•MCLR Reset during Sleep

• WDT Reset

• Brown-out Reset (BOR)

WDT wake-up does not cause register resets in the

same manner as a WDT Reset since wake-up is

viewed as the resumption of normal operation. TO and

PD bits are set or cleared differently in different Reset

situations, as indicated in Table 12-2. Software can use

these bits to determine the nature of the Reset. See

Table 12-4 for a full description of Reset states of all

registers.

A simplified block diagram of the On-Chip Reset Circuit

is shown in Figure 12-1.

The MCLR Reset path has a noise filter to detect and

ignore small pulses. See Section 15.0 “Electrical

Specifications” for pulse-width specifications.

FIGURE 12-1:

SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External

Reset

MCLR/VPP pin

VDD

OSC1/

WDT

Module

VDD Rise

Detect

OST/PWRT

LFINTOSC

WDT

Time-out

Power-on Reset

OST

10-bit Ripple Counter

PWRT

Chip_Reset

11-bit Ripple Counter

Reset

Enable OST

Enable PWRT

SLEEP

Brown-out(1)

Reset

SBOREN

BOREN

CLKI pin

Note 1:

Refer to the Configuration Word register (Register 12-1).

PIC16F684 датащи(PDF) 101 Page - Microchip Technology

PIC16F684 датащи(HTML) 101 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

датащи скачать

ссылки URL