PIC16F526-ISLASHP datasheet(55/122 Pages) MICROCHIP

55 / 122 page

 2010 Microchip Technology Inc.

DS41326D-page 55

PIC16F526

8.7

Time-out Sequence, Power-down

and Wake-up from Sleep Status

Bits (TO, PD, RBWUF, CWUF)

The TO, PD and RBWUF bits in the STATUS register

can be tested to determine if a Reset condition has

been caused by a power-up condition, a MCLR or

Watchdog Timer (WDT) Reset.

TABLE 8-7:

TO/PD/RBWUF/CWUF

STATUS AFTER RESET

8.8

Reset on Brown-out

A brown-out is a condition where device power (VDD)

dips below its minimum value, but not to zero, and then

recovers. The device should be reset in the event of a

brown-out.

To reset PIC16F526 devices when a brown-out occurs,

external brown-out protection circuits may be built, as

shown in Figure 8-12 and Figure 8-13.

FIGURE 8-12:

BROWN-OUT

PROTECTION CIRCUIT 1

FIGURE 8-13:

BROWN-OUT

PROTECTION CIRCUIT 2

FIGURE 8-14:

BROWN-OUT

PROTECTION CIRCUIT 3

CWUF RBWUF TO PD

Reset Caused By

0 WDT wake-up from

Sleep

u WDT time-out (not from

Sleep)

0 MCLR wake-up from

Sleep

1 Power-up

u MCLR not during Sleep

0 Wake-up from Sleep on

pin change

0 Wake up from Sleep on

comparator change

Legend: u = unchanged

Note 1: The TO, PD and RBWUF bits maintain

their status (u) until a Reset occurs. A

low-pulse on the MCLR input does not

change the TO, PD and RBWUF Status

bits.

Note 1:

This circuit will activate Reset when VDD goes

below Vz + 0.7V (where Vz = Zener voltage).

Pin must be configured as MCLR.

33k

10k

40k(1)

VDD

MCLR(2)

PIC12F510

VDD

PIC16F506

Note 1:

This brown-out circuit is less expensive,

although less accurate. Transistor Q1 turns

off when VDD is below a certain level such

that:

Pin must be configured as MCLR.

VDD •

R1 + R2

= 0.7V

40k(1)

VDD

MCLR(2)

PIC12F510

VDD

PIC16F506

Note:

This brown-out protection circuit employs

Microchip Technology’s MCP809 microcon-

troller supervisor. There are 7 different trip

point selections to accommodate 5V to 3V

systems.

MCLR

PIC12F510

VDD

VSS

RST

MCP809

VDD

Bypass

Capacitor

PIC16F506

PIC16F526-I/P 数据表(PDF) 55 Page - Microchip Technology

PIC16F526-I/P 数据表(HTML) 55 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

链接网址

PIC16F526-I/P 数据表(PDF) 55 Page - Microchip Technology

PIC16F526-I/P 数据表(HTML) 55 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

链接网址

数据表下载