Datasheet

V850ES/JG3 CHAPTER 13 A/D CONVERTER
R01UH0015EJ0300 Rev.3.00 Page 418 of 870
Sep 30, 2010
The relationship between the analog voltage input to the analog input pins (ANI0 to ANI11) and the A/D conversion
result (ADA0CRn register) is as follows.
V
IN
SAR = INT (
AV
REF0
× 1,024 + 0.5)
ADA0CR
Note
= SAR × 64
Or,
AV
REF0 AVREF0
(SAR − 0.5) ×
1,024
≤ VIN < (SAR + 0.5) ×
1,024
INT( ): Function that returns the integer of the value in ( )
V
IN: Analog input voltage
AV
REF0: AVREF0 pin voltage
ADA0CR: Value of ADA0CRn register
Note The lower 6 bits of the ADA0CRn register are fixed to 0.
The following shows the relationship between the analog input voltage and the A/D conversion results.
Figure 13-2. Relationship Between Analog Input Voltage and A/D Conversion Results
1,023
1,022
1,021
3
2
1
0
Input voltage/AV
REF0
1
2,048
1
1,024
3
2,048
2
1,024
5
2,048
3
1,024
2,043
2,048
1,022
1,024
2,045
2,048
1,023
1,024
2,047
2,048
1
A/D conversion results
ADA0CRn
SAR
FFC0H
FF80H
FF40H
00C0H
0080H
0040H
0000H