HD6417641 RENESAS [Renesas Technology Corp], HD6417641 Datasheet - Page 856

• Manufacturer Part Number: HD6417641
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 21 A/D Converter
21.3.2
Multi mode should be selected when performing A/D conversions on one or more channels. When
the ADST bit is set to 1 by software, A/D conversion starts on the first channel in the group (A/D0
when AN0, A/D1 when AN4). When two or more channels are selected, after conversion of the
first channel ends, conversion of the second channel (AN1 or AN5) starts immediately. When A/D
conversions end on the selected channels, the ADST bit is cleared to 0. The conversion results are
transferred for storage into the A/D data registers corresponding to the channels.
When the mode or analog input channel selection must be changed during A/D conversion, to
prevent incorrect operation, first clear the ADST bit to 0 to halt A/D conversion. After making the
necessary changes, set the ADST bit to 1. A/D conversion will start again from the first channel in
the group. The ADST bit can be set at the same time as the mode or channel selection is changed.
Rev. 4.00 Sep. 14, 2005 Page 806 of 982
REJ09B0023-0400
Channel 0 (AN0)
Channel 1 (AN1)
Channel 2 (AN2)
Channel 3 (AN3)
Figure 21.2 Example of A/D Converter Operation (Single Mode, Channel 1 Selected)
operating
operating
operating
operating
ADDRC
ADDRD
ADDRA
ADDRB
Multi Mode
Note: * Vertical arrows ( ) indicate instruction execution by software.
ADST
ADIE
ADF
A/D conversion starts
Waiting
Waiting
Waiting
Waiting
A/D conversion 1
Set*
Set*
A/D conversion result 2
A/D conversion result 1
Waiting
Clear*
Read result
Set*
A/D conversion result 2
Clear*
Read result
Waiting