Datasheet

Section 15 A/D Converter
Rev.7.00 Dec. 24, 2008 Page 543 of 698
REJ09B0074-0700
15.5.2 Scan Mode
In scan mode, A/D conversion is to be performed sequentially on the specified channels (four
channels maximum). The operations are as follows.
1. When the ADST bit is set to 1 by software, TPU or external trigger input, A/D conversion
starts on the first channel in the group (AN0 when CH3 and CH2 = 00, AN4 when CH3 and
CH2 = 01, or AN8 when CH3 and CH2 = 10).
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 flag 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.
4. Steps 2 to 3 are repeated as long as the ADST bit remains set to 1. When the ADST bit is
cleared to 0, A/D conversion stops.
ADST
ADF
ADDRA
ADDRB
ADDRC
ADDRD
State of
channel 0 (AN0)
State of
channel 1 (AN1)
State of
channel 2 (AN2)
State of
channel 3 (AN3)
Set*
1
Clear*
1
Idle
Notes: 1. Vertical arrows ( ) indicate instructions executed by software.
2. Data currently being converted is ignored.
Clear*
1
Idle
Idle
A/D conversion time
Continuous A/D conversion execution
A/D conversion 1
Idle Idle
Idle
Idle
Idle
Transfer
A/D conversion 4
A/D conversion result 1
A/D conversion result 2
A/D conversion result 3
A/D conversion result 4
Idle
A/D conversion 5 *
2
A/D conversion 3
A/D conversion 2
Figure 15.4 A/D Conversion Timing (Scan Mode, Channels AN0 to AN2 Selected)