227
CHAPTER 12 8-BIT A/D CONVERTER (
µ
PD780344, 780344Y SUBSERIES)
User’s Manual U15798EJ2V0UD
Figure 12-2. Format of A/D Converter Mode Register 0 (ADM0)
Address: FF80H After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
ADM0
ADCS0
TRG0
FR02
FR01
FR00
EGA01
EGA00
ADCE0
ADCS0
A/D conversion operation control
0
Stop conversion operation.
1
Enable conversion operation.
TRG0
Software start/hardware start selection
0
Software start
1
Hardware start
FR02
FR01
FR00
Conversion time selection
Note 1
0
0
0
144/f
X
(14.4
µ
s)
0
0
1
120/f
X
(Setting prohibited
Note 2
)
0
1
0
96/f
X
(Setting prohibited
Note 2
)
1
0
0
576/f
X
(57.6
µ
s)
1
0
1
480/f
X
(48.0
µ
s)
1
1
0
384/f
X
(38.4
µ
s)
Other than above
Setting prohibited
EGA01
EGA00
External trigger signal edge specification
0
0
No edge detection
0
1
Falling edge detection
1
0
Rising edge detection
1
1
Both falling and rising edge detection
ADCE0
Control of voltage booster for A/D converter circuit
Note 3
0
Stops operation.
1
Enables operation.
Notes 1.
Set so that the A/D conversion time is 14
µ
s or more.
2.
Setting prohibited because A/D conversion time is less than 14
µ
s at f
X
= 10 MHz.
3.
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 ADCE0, and it takes 14
µ
s from operation
start to operation stabilization. Therefore, when ADCS0 is set to 1 after 14
µ
s or more has elapsed
from the time ADCE0 is set to 1, the conversion result at that time has priority over the first conversion
result.
Remarks 1.
f
X
: Main system clock oscillation frequency
2.
Figures in parentheses are for operation with f
X
= 10 MHz.
Содержание mPD780344 Series
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