M16C62_M Datasheet, PDF (453/615 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 2.7.13. Variation of the successive comparison register and Vref while A-D conversion is in
progress (8-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 000000000
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
2
±
VREF
4
±
VREF
8
–
VREF
2048
[V]
n8 = 1
n8 = 0
+
–
VREF
8
VREF
8
8th comparison
Conversion
complete
n9 n8 n7 n6 n5 n4 n3 1 0 0
n9 n8 n7 n6 n5 n4 n3 n2 0 0
VREF _± VREF
2
4
± ^VREF
8
± ...... ± ^VREF
256
–
VREF
2048
[V]
This data transfers to bit 0 to
bit 7 of A-D register i.
Result of A-D conversion
FF16
FE16
Theoretical A-D conversion
characteristic of general 8-bit
A-D converter
0316
0216
0116
0016
0
VREF _{x 3}
2048
Theoretical A-D conversion
characteristic in the 8-bit mode
VREF _{x 1}
256
VREF _{x 2}
256
VREF _{x 3}
256
VREF _{x 4}
256
VREF _{x 254} VREF _{x 255}
256
256
VREF
Analog input voltage
Figure 2.7.25. Theoretical A-D conversion characteristics (8-bit mode)
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