FUJITSU MB91F109 FR30 User Manual
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CHAPTER 11 A/D CONVERTER (Successive approximation type)
11.1 Overview of A/D Converter (Successive Approximation
Type)
The A/D converter converts analog input voltage to digital values.
■
Characteristics of A/D Converter
•
Minimum conversion time: 5.6
µ
s/ch (for 25 MHz system clock)
•
Built-in sample & hold circuit
•
10- bit resolution
•
Program selection of analog input from four channels
•
Single conversion mode: One channel is selected and converted.
•
Scan conversion mode: Multiple consecutive channels are converted. Up to four
channels can be programmed.
•
Continuous conversion mode: The specified channel is converted repeatedly.
•
Convert-and-stop mode: When one channel is converted, the converter stops and waits
for the next activation (the beginning of conversion can be synchronized).
•
DMA transfer activated by an interrupt
•
Choices of software, external trigger (falling edge), and reload timer (rising edge) for
activation
■
A/D Converter Registers
Figure 11.1-1 shows the A/D converter registers.
Figure 11.1-1 A/D Converter Registers
15
0
ADCS
ADCR
16bit
bit
15
14
13
12
11
10
9
8
BUSY
INT
INTE PAUS STS1 STS0 STRT
(ADCS)
bit
7
6
5
4
3
2
1
0
MD1
MD0
ANS2 ANS1 ANS0 ANE2 ANE1 ANE0
bit
15
14
13
12
11
10
9
8
(ADCR)
bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
9
8
Control status register
Data register