upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 225

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

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11.3 Registers Used in A/D Converter
(1) A/D converter mode register (ADM)
The following five registers are used to control the A/D converter.
This register sets the conversion time for analog input to be A/D converted, and starts/stops conversion.
ADM can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Notes 1. Set so that the A/D conversion time is as follows.
A/D converter mode register (ADM)
Analog input channel specification register (ADS)
A/D conversion result register (ADCR)
Power-fail comparison mode register (PFM)
Power-fail comparison threshold register (PFT)
2. A booster circuit is incorporated to realize low-voltage operation. The operation of the circuit that
generates the reference voltage for boosting is controlled by ADCE, and it takes 14 s from operation
start to operation stabilization. Therefore, when ADCS is set to 1 after 14 s or more has elapsed from
the time ADCE is set to 1, the conversion result at that time has priority over the first conversion result.
Standard products, (A) grade products: 14 s or longer but less than 100 s
(A1) grade products: 14 s or longer but less than 60 s
Address: FF28H
Symbol
ADM
Figure 11-3. Format of A/D Converter Mode Register (ADM)
ADCS
ADCS
ADCE
FR2
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0
1
0
0
0
1
1
1
0
1
Other than above
Stops conversion operation
Enables conversion operation
Stops operation of reference voltage generator
Enables operation of reference voltage generator
After reset: 00H
FR1
6
0
0
0
1
0
0
1
Boost reference voltage generator operation control
CHAPTER 11 A/D CONVERTER
User’s Manual U16961EJ4V0UD
FR2
FR0
5
0
1
0
0
1
0
A/D conversion operation control
288/f
240/f
192/f
144/f
120/f
96/f
Setting prohibited
R/W
FR1
4
X
X
X
X
X
X
Conversion time selection
f
144 s
120 s
96 s
72 s
60 s
48 s
X
= 2 MHz
FR0
3
f
X
34.3 s
28.6 s
22.9 s
17.2 s
14.3 s
11.5 s
= 8.38 MHz f
2
0
X
28.8 s
24.0 s
19.2 s
14.4 s
12.0 s
9.6 s
= 10 MHz
1
0
Note 1
Note 2
f
18 s
15 s
12 s
9 s
7.5 s
6 s
X
ADCE
= 16 MHz
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