SNAD01C

8-CHANNEL 8-BIT ADC

(1) Command ID: (100)

(2) 3-bit channel number data behind command ID.

(3) The analog signal of the selected channel is sampled to ADC. ADC refers the reference

voltage and converts the sampled analog signal to digital domain by successive-

approximation method.

(4) The 8-bit output data (result of conversion) of ADC is sent to DIO port from MSB and is

triggered by CLK. The maximum clock frequency is 500kHz @ 2.7v. (Maximum conversion

rate=25KHz)

(5) After the 8-bits ADC data has been sent out, if the START is kept in LOW and CLK is kept in

High/Low transition, then the data with uncertain value are kept appearing on DIO. These

data can just be ignored.

Channel ID[2:0]

Selected Channel

000

CH0

001

CH1

010

CH2

011

CH3

100

CH4

101

CH5

110

CH6

111

CH7

Table-4 Channel Selection Table

6.5. Timing of Digital Input Reading

CLK

START

Digital Input

Reading

HiZ

CM

2

CM

1

CM0

DI[7] DI[6] DI[5] DI[4]

DI[3] DI[2] DI[1] DI[0]

DI[3]

DI[7] DI[6] DI[5] DI[4]

DIO

Port Output

Port Input

Figure-7 The timing diagram of the digital input reading

Version: 1.5

July 31, 2003

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