ST7262 datasheet(89/132 Pages) STMICROELECTRONICS

89 / 132 page

ST7262

89/132

10-BIT A/D CONVERTER (ADC) (Cont’d)

10.7.3.4 A/D Conversion

Conversion can be performed in One-Shot or Con-

tinuous mode. Continuous mode is typically used

for monitoring a single channel. One-shot mode

should be used when the application requires in-

puts from several channels.

ADC Configuration

The analog input ports must be configured as in-

put, no pull-up, no interrupt. Refer to the «I/O

ports» chapter. Using these pins as analog inputs

does not affect the ability of the port to be read as

a logic input.

In the ADCCSR register:

– Select the CS[2:0] bits to assign the analog

channel to convert.

ADC One-Shot Conversion mode

In the ADCCSR register:

1.Set the ONE SHOT bit to put the A/D converter

in one shot mode.

2.Set the ADON bit to enable the A/D converter

and to start the conversion. The EOC bit is kept

low by hardware during the conversion.

Note: Changing the A/D channel during conver-

sion will stop the current conversion and start con-

version of the newly selected channel.

When a conversion is complete:

– The EOC bit is set by hardware.

– An interrupt request is generated if the ITE bit

is set.

– The ADON bit is reset by hardware.

– The result is in the ADCDR registers.

To read the 10 bits, perform the following steps:

1. Wait for interrupt or poll the EOC bit

2. Read ADCDRLSB

3. Read ADCDRMSB

The EOC bit is reset by hardware once the AD-

CDRMSB is read.

Figure 51. ADC Block Diagram

CS2

CS1

EOC SPEED ADON

ITE

CS0

ADCCSR

AIN0

AIN1

ANALOG TO DIGITAL

CONVERTER

AINx

ANALOG

MUX

ADCDRMSB

DIV 2

fADC

fCPU

ADCDRLSB

DIV 4

EOC Interrupt

0000

ONE

SHOT

ST7262 데이터시트(PDF) 89 Page - STMicroelectronics

ST7262 데이터시트(HTML) 89 Page - STMicroelectronics

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

데이터시트 다운로드

링크 URL