UPD78F0138 NEC, UPD78F0138 Datasheet - Page 254

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

12.3 Registers Used in A/D Converter
(1) A/D converter mode register (ADM)
254
The A/D converter uses the following five registers.
• 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)
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.
Address: FF28H
Symbol
ADM
Figure 12-2. Format of A/D Converter Mode Register (ADM)
ADCS
ADCS
ADCE
FR2
<7>
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 12 A/D CONVERTER
User’s Manual U16228EJ2V0UD
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
FR0
= 2 MHz
3
f
34.3 s
28.6 s
22.9 s
17.2 s
14.3 s
11.5 s
2
0
X
= 8.38 MHz f
1
0
Note 1
28.8 s
24.0 s
19.2 s
14.4 s
12.0 s
9.6 s
X
= 10 MHz
Note 2
ADCE
<0>