RX610 Group
23. A/D Converter
R01UH0032EJ0120 Rev.1.20
Page 788 of 1006
Feb 20, 2013
23.3
Operation
The RX610 Group includes four units of A/D converter and the each unit has a same feature.
Definitions of a single unit are given below.
The A/D converter has two operating modes: single mode and scan mode.
In single mode, A/D conversion is to be performed for only once on the analog input of the specified single channel.
In scan mode, A/D conversion is to be performed sequentially on the analog inputs of the specified channels up to four.
Two types of scan mode are provided, that is, continuous san mode where A/D conversion is repeatedly performed and
single scan mode where A/D conversion is performed for the specified channels for one cycle.
23.3.1
Single Mode
In single mode, A/D conversion is to be performed for only once on the analog input of the specified single channel as
below.
1. A/D conversion for the selected channel is started when the ADST bit in ADCSR is set to 1 (A/D conversion start)
by software, TPU, TMR, or an external trigger input.
2. When A/D conversion is completed, the A/D conversion result is stored into the corresponding A/D data register
(ADDRn) of the channel.
3. When A/D conversion is completed, if the ADIE bit in ADCSR is set to 1 (A/D interrupt enable by completing A/D
conversion), an ADI interrupt request is generated.
4. The ADST bit remains at 1 during A/D conversion, and is automatically cleared to 0 when A/D conversion ends.
Then the A/D converter enters a wait state.
5. If the ADST bit is cleared to 0 during A/D conversion (A/D conversion stop), A/D conversion stops and the A/D
converter enters a wait state.
Figure 23.5 shows an example of operation when AN1 is selected as an analog input.