Module Stop Mode Setting; Note On Activation Of The A/D Converter By An External Trigger - Renesas H8S/2100 Series Hardware Manual

6-bit single-chip microcomputer

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Section 22 A/D Converter

Module Stop Mode Setting

When this LSI enters software standby mode with A/D conversion enabled, the analog inputs are

retained, and the analog power supply current is equal to the current as during A/D conversion. If

the analog power supply current needs to be reduced in software standby mode, clear the ADST,

TRGS1, and TRGS0 bits all to 0 to disable A/D conversion.

When starting of the A/D converter by an external trigger* is in use, any of the following actions

(1. to 3.) may lead to a situation where stopping of the A/D converter is not possible.

Note: * External trigger: Conversion-start trigger from the peripheral modules (TMU and TPU)

1. Changing the value of the ADST bit in ADCSR from 0 to 1

2. Changing from the activation by external trigger setting to the external-trigger-disabled setting

3. Changing the scan-mode setting (changing the setting of the SCANE and ADSTCLR bits to

switch from continuous scan mode to single mode or one-cycle scan mode)

If any of the above points is applicable, please make settings in accord with the instructions below.

If 1. is applicable:

Do not set the ADST bit in ADCSR to 1.

If 2. or 3. is applicable:

Be sure to invalidate the external trigger input before changing the setting from activation by the

external trigger to disabling of the external trigger or changing the scan-mode setting (changing

the setting of the SCANE and ADSTCLR bits) while activation by the external trigger is in use.

Rev. 1.00 May 09, 2008 Page 710 of 954

REJ09B0462-0100

Note: Values are reference values.

Figure 22.7 Analog Input Pin Equivalent Circuit

To A/D converter