7480 datasheet(246/337 Pages) RENESAS

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7480 Group and 7481 Group User's Manual

2-31

APPLICATIONS

Figure 2.4.2 Control Procedure Example of Determining A-D Conversion Values

2.4 A-D Converter

Set A-D conversion control register

ADCON (Address 00D916)

Analog input pin : P20/IN0

A-D conversion routine

00 0

VREF stabilizing wait time

A-D conversion completed ? (Note)

END

A-D conversion completion interrupt request bit

← ‘0’

Connect between VREF pin

and ladder resistor

Average of 4-time samplings, which the maximum

value and the minimum value are excluded from

6-time samplings, is calculated.

Update of determined value

(The last calculated average value becomes

the determined value)

The difference from previous

determined value is less than 5 ?

Note: The completion of A-D conversion is examined by the following.

• A-D conversion completion bit of A-D conversion control register is ‘1’.

• A-D conversion completion interrupt request bit of interrupt request register 1 is ‘1’.

• Branch to A-D conversion completion interrupt service routine is performed.

(When A-D conversion completion interrupt is enabled)

A-D conversion start

00 0

Set A-D conversion control register

ADCON (Address 00D916)

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