MB90470 Series
39
4.
8/10-bit A/D Converter
The A/D converter converts analog input voltages into digital values, and provides the following features :
Conversion time : minimum 4.9
s per channel
(at 98 machine cycles/machine clock 20 MHz, including sampling time)
Sampling time : minimum 3.0
s per channel
(at 60 machine cycles/machine clock 20 MHz)
Uses RC sequential comparison conversion with sample & hold circuit.
Selection of 8- or 10-bit resolution
Analog input from 8 channels, by program selection
Single conversion mode : Convert 1 selected channel
Scan conversion mode : Convert multiple consecutive channels. Select up to 8 channels by program selection.
Continuous conversion mode : Convert specified channel continuously.
Stop conversion mode : Convert one channel, pause and stand by until the next start. (Simultaneous conversion
start available.)
At the end of A/D conversion, an A/D conversion end interrupt request can be sent to the CPU. This interrupt
request can start the
DMA and transfer the conversion data to memory, making it ideal for continuous
processing.
Start sources include selection of software, external trigger (falling edge) , or timer (rising edge) .
(1) Register List
ADCS2, ADCS1 (Control status registers)
ADCR2, ADCR1 (Data registers)
ADCS1
Address : 000046H
←Default value
←Bit attributes
ADCS2
bit
Address : 000047H
←Default value
←Bit attributes
ADCR1
bit
Address : 000048H
←Default value
←Bit attributes
ADCR2
bit
Address : 000049H
←Default value
←Bit attributes
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
76
5
4
3
2
1
0
MD0
0
R/W
MD1
ANS2
ANS1
ANS0
ANE2
ANE1
ANE0
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
W
0
R/W
15
14
13
12
11
10
9
8
INT
0
R/W
BUSY
INTE
PAUS
STS1
STS0
STRT
Reserved
X
R
X
R
X
R
X
R
X
R
X
R
X
R
76
5
4
3
2
1
0
D6
X
R
D7
D5
D4
D3
D2
D1
D0
0
W
0
W
0
W
0
W
X
R
X
R
X
R
15
14
13
12
11
10
9
8
ST1
0
R/W
S10
ST0
CT1
CT0
D9
D8