Advertisement
ADIE
A/D conversion
starts
ADST
ADF
State of channel 0
Idle
(AN0)
State of channel 1
Idle
(AN1)
State of channel 2
Idle
(AN2)
State of channel 3
Idle
(AN3)
ADDRA
ADDRB
ADDRC
ADDRD
Note : *
indicates execution of a software instruction.
23.4.2
Scan Mode
In scan mode, A/D conversion is performed sequentially on the specified channels (four channels
or eight channel maximum). Operations are as follows.
1. When the ADST bit in ADCSR is set to 1 by software or by the input of trigger signal, A/D
conversion starts from the first channel of the selected channel. Consecutive A/D conversion of
either four channels maximum (SCANE and SCANS = B'10) or eight channels maximum
(SCANE and SCANS = B'11) can be selected. In the case of consecutive A/D conversion on
four channels, the operation starts from AN0 when CH2 = B'0, and starts from AN4 when CH2
= B'1. In the case of consecutive A/D conversion on eight channels, the operation starts from
AN0.
2. When A/D conversion for each channel is completed, the result is sequentially transferred to
the A/D data register corresponding to each channel.
3. When conversion of all the selected channels is completed, the ADF bit in ADCSR is set to 1.
If the ADIE bit is set to 1 at this time, an ADI interrupt is requested after A/D conversion ends.
Conversion of the first channel in the group starts again.
Set*
Set*
A/D conversion 1
Figure 23.2 Example of A/D Converter Operation
(When Channel 1 is Selected in Single Mode)
Set*
Clear*
Idle
A/D conversion 2
Read the result of conversion
Result of A/D conversion 1
Rev. 1.00 Mar. 12, 2008 Page 903 of 1178
Section 23 A/D Converter
Clear*
Idle
Read the result of conversion
Result of A/D conversion 2
REJ09B0403-0100
Advertisement
