Operation; Single Mode - Renesas H8S/2100 Series Hardware Manual

22.4

Operation

The A/D converter operates by successive approximation with 10-bit resolution. It has two
operating modes: single mode and scan mode. First, select the clock used in A/D conversion.
When changing the operating mode or analog input channel, to prevent incorrect operation, first
clear the ADST bit in ADCSR to 0 to halt A/D conversion. The ADST bit can be set at the same
time the operating mode or analog input channel is changed.
22.4.1

Single Mode

In single mode, A/D conversion is to be performed only once on the specified single channel.
Operations are as follows.
1. A/D conversion on the specified channel is started when the ADST bit in ADCSR is set to 1 by
software, the TMR, or the TPU.
2. When A/D conversion is completed, the result is transferred to the A/D data register
corresponding to the channel.
3. On completion of A/D conversion, the ADF bit in ADCSR is set to 1. If the ADIE bit is set to
1 at this time, an ADI interrupt request is generated.
4. The ADST bit remains set to 1 during A/D conversion. When conversion ends, the ADST bit
is automatically cleared to 0 and the A/D converter enters wait state. When the ADST bit is
cleared to 0 during A/D conversion, the conversion stops and the A/D converter enters wait
state.
Section 22 A/D Converter
Rev. 1.00 Apr. 28, 2008 Page 735 of 994
REJ09B0452-0100