UPD78F9500MA-CAC-A Datasheet, PDF (164/342 Pages) Renesas Technology Corp – 8-Bit Single-Chip Microcontrollers

CHAPTER 9 A/D CONVERTER (μPD78F920x ONLY)
Figure 9-3. Format of A/D Converter Mode Register (ADM)
Address: FF80H After reset: 00H R/W
Symbol
<7>
6
5
4
3
2
1
ADM
ADCS
0
FR2
FR1
FR0
0
0
<0>
ADCE
ADCS
0
1^{Note 1}
Stops conversion operation
Starts conversion operation
A/D conversion operation control
FR2
0
1
1
1
0
0
1
0
FR1
0
0
1
0
1
0
1
1
FR0
0
0
0
1
0
1
1
1
Reference
Voltage
Range^{Note 2}
Sampling
Time^{Note 3}
Conversion
Time^{Note 4}
fXP = 8 MHz
Sampling Conversion
Time^{Note 3}
Time^{Note 4}
fXP = 10 MHz
Sampling Conversion
Time^{Note 3}
Time^{Note 4}
VDD ≥
4.5 V
12/fXP
36/fXP
1.5 μs
4.5 μs
1.2 μs
3.6 μs
VDD ≥
4.0 V
24/fXP
72/fXP
3.0 μs
9.0 μs
2.4 μs
7.2 μs
VDD ≥
2.85 V
96/fXP
48/fXP
144/fXP
96/fXP
12.0 μs
6.0 μs
18.0 μs
12.0 μs
9.6 μs
4.8 μs
14.4 μs
9.6 μs
48/fXP
72/fXP
6.0 μs
9.0 μs
4.8 μs
7.2 μs
24/fXP
48/fXP
3.0 μs
6.0 μs
Setting
prohibited
Note 5
Setting
prohibited
Note 5
(2.4 μs) (4.8 μs)
VDD ≥
2.7 V
176/fXP
88/fXP
224/fXP
112/fXP
22.0 μs
11.0 μs
28.0 μs
14.0 μs
17.6 μs
Setting
prohibited
Note 5
22.4 μs
Setting
prohibited
Note 5
(8.8 μs) (11.2 μs)
ADCE
0^{Note 1}
Stops operation of comparator
Comparator operation control^{Note 6}
1
Enables operation of comparator
Remarks 1. fXP: Oscillation frequency of clock to peripheral hardware
2. The conversion time refers to the total of the sampling time and the time from successively
comparing with the sampling value until the conversion result is output.
Notes 1. Even when the ADCE = 0 (comparator operation stopped), the A/D conversion operation starts if
the ADCS is set to 1. However, the data of the first conversion is out of the guaranteed-value
range, so ignore it.
2. Be sure to set the FR2, FR1, and FR0, in accordance with the reference voltage so that Notes 2
and 3 below are satisfied.
Example When VDD ≥ 2.7 V, fXP = 8 MHz
• The sampling time is 11.0 μs or more and the A/D conversion time is 14.0 μs or
more and 100 μs or less.
• Set FR2, FR1, and FR0 = 0, 1, 1 or 1, 1, 1.
162
User’s Manual U18172EJ3V0UD