M30622MA-XXXFP RENESAS [Renesas Technology Corp], M30622MA-XXXFP Datasheet - Page 420

• Manufacturer Part Number: M30622MA-XXXFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY
• Manufacturer: RENESAS [Renesas Technology Corp]

A-D Converter
Table 2.7.10. Relationship of the successive comparison register contents and Vref
2.7.11 Method of A-D Conversion (10-bit mode)
Successive approximation register : n
(1) The A-D converter compares the reference voltage (Vref) generated internally based on the
contents of the successive comparison register with the analog input voltage (V
the analog input pin. Each bit of the comparison result is stored in the successive comparison
register until analog-to-digital conversion (successive comparison method) is complete. If a
trigger occurs, the A-D converter carries out the following:
Vref is generated based on the latest content of the successive comparison register. Table
2.7.10 shows the relationship of the successive comparison register contents and Vref. Table
2.7.11 shows how the successive comparison register and Vref vary while A-D conversion is
in progress. Figure 2.7.23 shows theoretical A-D conversion characteristics.
1. Fixes bit 9 of the successive comparison register.
2. Fixes bit 8 of the successive comparison register.
3. Fixes bit 7 through bit 0 of the successive comparison register.
Compares Vref with V
register are “1000000000
Bit 9 of the successive comparison register varies depending on the comparison re-
sult as follows.
Sets bit 8 of the successive comparison register to “1”, then compares Vref with V
Bit 8 of the successive comparison register varies depending on the comparison
result as follows:
Carries out step 2 above on bit 7 through bit 0.
After bit 0 is fixed, the contents of the successive comparison register (conversion
result) are transmitted to A-D register i.
1 to1023
If Vref < V
If Vref > V
If Vref < V
If Vref > V
0
IN
IN
IN
IN
, then “1” is assigned to bit 9.
, then “0” is assigned to bit 9.
, then “1” is assigned to bit 8.
, then “0” is assigned to bit 8.
IN
: [In this instance, the contents of the successive comparison
2
” (default).]
1024
V
REF
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
x
Vref (V)
0
n
–
Mitsubishi microcomputers
V
2048
M16C / 62 Group
REF
IN
) input from
IN
405
.