PIC16F818-ESLASHML datasheet(83/176 Pages) MICROCHIP

83 / 176 page

 2003 Microchip Technology Inc.

DS39598D-page 81

PIC16F818/819

11.0

ANALOG-TO-DIGITAL

CONVERTER (A/D) MODULE

The Analog-to-Digital (A/D) converter module has five

inputs for 18/20 pin devices.

The conversion of an analog input signal results in a

corresponding 10-bit digital number. The A/D module

has a high and low-voltage reference input that is

software selectable to some combination of VDD, VSS,

RA2 or RA3.

The A/D converter has a unique feature of being able

to operate while the device is in Sleep mode. To oper-

ate in Sleep, the A/D conversion clock must be derived

from the A/D’s internal RC oscillator.

The A/D module has four registers:

• A/D Result High Register (ADRESH)

• A/D Result Low Register (ADRESL)

• A/D Control Register 0 (ADCON0)

• A/D Control Register 1 (ADCON1)

The

ADCON0

shown

controls the operation of the A/D module. The

ADCON1 register, shown in Register 11-2, configures

the functions of the port pins. The port pins can be

configured as analog inputs (RA3 can also be a voltage

reference) or as digital I/Os.

Additional information on using the A/D module can be

found in the “PICmicro® Mid-Range MCU Family

Reference Manual” (DS33023).

ADCON0: A/D CONTROL REGISTER 0 (ADDRESS 1Fh)

R/W-0

U-0

R/W-0

ADCS1

ADCS0

CHS2

CHS1

CHS0

GO/DONE

—ADON

bit 7

bit 0

bit 7-6

ADCS1:ADCS0: A/D Conversion Clock Select bits

If ADCS2 = 0:

= FOSC/2

= FOSC/8

= FOSC/32

= FRC (clock derived from the internal A/D module RC oscillator)

If ADCS2 = 1:

= FOSC/4

= FOSC/16

= FOSC/64

= FRC (clock derived from the internal A/D module RC oscillator)

bit 5-3

CHS2:CHS0: Analog Channel Select bits

000

= Channel 0 (RA0/AN0)

001

= Channel 1 (RA1/AN1)

010

= Channel 2 (RA2/AN2)

011

= Channel 3 (RA3/AN3)

100

= Channel 4 (RA4/AN4)

bit 2

GO/DONE: A/D Conversion Status bit

If ADON = 1:

= A/D conversion in progress (setting this bit starts the A/D conversion)

= A/D conversion not in progress (this bit is automatically cleared by hardware when the

A/D conversion is complete)

bit 1

Unimplemented: Read as ‘0’

bit 0

ADON: A/D On bit

= A/D converter module is operating

= A/D converter module is shut-off and consumes no operating current

Legend:

R = Readable bit

W = Writable bit

U = Unimplemented bit, read as ‘0’

-n = Value at POR

‘1’ = Bit is set

‘0’ = Bit is cleared

x = Bit is unknown

PIC16F818-E/ML датащи(PDF) 83 Page - Microchip Technology

PIC16F818-E/ML датащи(HTML) 83 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