RX610 Group
23. A/D Converter
R01UH0032EJ0120 Rev.1.20
Page 792 of 1006
Feb 20, 2013
23.3.2.2
Single Scan Mode
In single scan mode, A/D conversion is to be performed for one cycle on the analog inputs of the specified channels as
below.
1. When the ADST bit in ADCSR is set to 1 (A/D conversion start) by software, TPU, TMR, or an external trigger
input, A/D conversion starts on the first channel in the specified channel group.
2. When A/D conversion for each channel is completed, the A/D conversion result is stored into the corresponding
A/D data registers (ADDRy).
3. When A/D conversion of all selected channels 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 (A/D conversion start) during A/D conversion, and is automatically cleared to 0 when
A/D conversion of all selected channels end. The A/D converter enters a wait state.
Figure 23.7 shows an example of A/D conversion when three channels (AN4 to AN6) are selected for analog input.
Set
*
ADCSR.ADST
A/D conversion start
Channel 4 (AN4)
Standby for conversion
Channel 5 (AN5)
Standby for conversion
Channel 6 (AN6)
Standby for conversion
Channel 7 (AN7)
Standby for conversion
ADDRA
ADDRB
ADDRC
ADDRD
ADI1
A/D conversion 1
(1)
(2)
Store
A/D conversion 2
Interrupt genera ion
Standby for conversion
Note:
*
indicates an instruction execution by software.
A/D conversion 3
A/D conversion result 1
Standby for conversion
A/D conversion result 2
A/D conversion result 3
A/D conversion time
Execute A/D conversion for once
(2)
(2)
(3)
(4)
Standby for conversion
Figure 23.7 Example of A/D Converter Operation (Single Scan Mode)