Section 20
A/D Converter (ADC)
Rev. 0.50 May 18, 2006 Page 1003 of 1588
REJ09B0313-0050
20.4.2 Multi
Mode
Multi mode should be selected when performing A/D conversion once on one or more channels.
In multi mode, A/D conversion is performed once for a maximum of eight specified analog input
channels, as follows:
1. A/D conversion starts from the analog input channel with the lowest number (e.g. AN0, AN1,
…, AN3) when the ADST bit in ADCSR is set to 1 by software, MTU2, or external trigger
input.
2. When A/D conversion is completed on each channel, the A/D conversion result is sequentially
transferred to the A/D data register corresponding to that channel.
3. After A/D conversion on all selected channels has completed, the ADF bit in ADCSR is set to
1. If the ADIE bit is set to 1 at this time, an ADI interrupt request is generated.
4. The ADST bit that remains 1 during A/D conversion is automatically cleared to 0 when A/D
conversion is completed, and the A/D converter becomes idle. If the ADST bit is cleared to 0
during A/D conversion, A/D conversion is halted and the A/D converter becomes idle. The
ADF bit is cleared by reading ADF while ADF = 1, then writing 0 to the ADF bit.
A/D conversion is to be performed once on all the specified channels. The conversion results are
transferred for storage into the A/D data registers corresponding to the channels.
When the operating 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.
Typical operations when three channels (AN0 to AN2) are selected in multi mode are described
next. Figure 20.3 shows a timing diagram for this example.
1. Multi mode is selected (MDS2 = 1, MDS1 = 0), analog input channels AN0 to AN2 are
selected (CH[2:0] = 010), and A/D conversion is started (ADST = 1).
2. A/D conversion of the first channel (AN0) starts. When A/D conversion is completed, the A/D
conversion result is transferred into ADDRA.
3. Next, the second channel (AN1) is selected automatically and A/D conversion starts.
4. Conversion proceeds in the same way through the third channel (AN2).
5. When conversion of all selected channels (AN0 to AN2) is completed, the ADF flag is set to 1
and the ADST bit cleared to 0.
6. If the ADIE bit is set to 1 at this time, an ADI interrupt is requested.
Summary of Contents for Single-Chip Microcomputer SH7203
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Page 52: ...Section 1 Overview Rev 0 50 May 18 2006 Page 22 of 1588 REJ09B0313 0050 ...
Page 98: ...Section 2 CPU Rev 0 50 May 18 2006 Page 68 of 1588 REJ09B0313 0050 ...
Page 128: ...Section 4 Clock Pulse Generator CPG Rev 0 50 May 18 2006 Page 98 of 1588 REJ09B0313 0050 ...
Page 200: ...Section 6 Interrupt Controller INTC Rev 0 50 May 18 2006 Page 170 of 1588 REJ09B0313 0050 ...
Page 242: ...Section 8 Cache Rev 0 50 May 18 2006 Page 212 of 1588 REJ09B0313 0050 ...
Page 400: ...Section 9 Bus State Controller BSC Rev 0 50 May 18 2006 Page 370 of 1588 REJ09B0313 0050 ...
Page 696: ...Section 13 Watchdog Timer WDT Rev 0 50 May 18 2006 Page 666 of 1588 REJ09B0313 0050 ...
Page 726: ...Section 14 Realtime Clock RTC Rev 0 50 May 18 2006 Page 696 of 1588 REJ09B0313 0050 ...
Page 876: ...Section 17 I2 C Bus Interface 3 IIC3 Rev 0 50 May 18 2006 Page 846 of 1588 REJ09B0313 0050 ...
Page 1054: ...Section 21 D A Converter DAC Rev 0 50 May 18 2006 Page 1024 of 1588 REJ09B0313 0050 ...
Page 1294: ...Section 24 LCD Controller LCDC Rev 0 50 May 18 2006 Page 1264 of 1588 REJ09B0313 0050 ...
Page 1386: ...Section 26 I O Ports Rev 0 50 May 18 2006 Page 1356 of 1588 REJ09B0313 0050 ...
Page 1512: ...Section 30 List of Registers Rev 0 50 May 18 2006 Page 1482 of 1588 REJ09B0313 0050 ...
Page 1598: ...Section 31 Electrical Characteristics Rev 0 50 May 18 2006 Page 1568 of 1588 REJ09B0313 0050 ...
Page 1606: ...Appendix Rev 0 50 May 18 2006 Page 1576 of 1588 REJ09B0313 0050 ...
Page 1618: ...Rev 0 50 May 18 2006 Page 1588 of 1588 REJ09B0313 0050 ...
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