M16C62_M Datasheet, PDF (451/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

A-D Converter
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Table 2.7.11. Variation of the successive comparison register and Vref while A-D conversion is in
progress (10-bit mode)
Successive approximation register
Vref change
b9
b0
A-D converter stopped 1 0 0 0 0 0 0 0 0 0
1st comparison
1 00 0 0 0 00 0 0
2nd comparison
3rd comparison
n9 1 0 0 0 0 0 0 0 0
1st comparison result
n9 n8 1 0 0 0 0 0 0 0
2nd comparison result
VREF _[V]
2
VREF
2
–
VREF
2048
[V]
VREF
2
±
VREF
4
–
VREF
2048
[V]
n9 = 1
n9 = 0
+
VREF
4
– ^VREF
4
VREF _± VREF _± VREF _– VREF _[V] ^{n8 = 1 +}
2
4
8
2048
n8 = 0 –
VREF
8
VREF
8
10th comparison
n9 n8 n7 n6 n5 n4 n3 n2 n1 0
VREF
2
±
VREF
4
±
VREF
8
± ...... ± ^VREF – ^VREF
1024 2048
[V]
Conversion complete n9 n8 n7 n6 n5 n4 n3 n2 n1 n0
This data transfers to the bit 0
to bit 9 of A-D register i.
Result of A-D conversion
3FF16
3FE16
Theoretical A-D
conversion characteristic
00316
00216
00116
00016
0
VREF _{x 1}
1024
VREF
1024
x
0.5
VREF _{x 2}
1024
VREF _{x 3}
1024
Ideal A-D conversion
characteristic
VREF _{x 1021} VREF _{x 1022} VREF _{x 1023}
1024
1024
1024
VREF
Analog input voltage
Figure 2.7.23. Theoretical A-D conversion characteristics (10-bit mode)
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