CHAPTER 11 A/D CONVERTER
519
User’s Manual U15195EJ5V0UD
(2) A/D scan mode registers 01 and 11 (ADSCM01, ADSCM11)
The ADSCMn1 registers are 16-bit registers that set the conversion time of the A/D converter.
They can be read or written in 16-bit units.
When the higher 8 bits of the ADSCMn1 register are used as the ADSCMn1H register, and the lower 8 bits
are used as the ADSCMn1L register, the ADSCMn1H register can be read/written in 8-bit units, and the
ADSCMn1L register is read-only, in 8-bit units.
Caution Do not write to the ADSCMn1 registers during an A/D conversion operation. If a write is
performed, the conversion operation is suspended and subsequently terminates.
14
0
13
0
12
0
2
0
3
0
4
0
5
0
6
0
7
0
8
FR0
9
FR1
10
FR2
11
0
15
0
1
0
0
0
14
0
13
0
12
0
2
0
3
0
4
0
5
0
6
0
7
0
8
FR0
9
FR1
10
FR2
11
0
15
0
1
0
0
0
ADSCM01
Address
FFFFF202H
After reset
0000H
ADSCM11
Address
FFFFF242H
After reset
0000H
Bit position
Bit name
Function
Specifies conversion time.
Conversion
time
(
µ
s)
Note
FR2 FR1 FR0 Conversion
clocks
f
XX
= 40 MHz
f
XX
= 33 MHz
0 0 0
344
8.60
−
0 0 1
248
6.20
7.51
0 1 0
176
−
5.33
0 1 1
128
−
−
1 0 0
104
−
−
1 0 1
80
−
−
1 1 0
56
−
−
1 1 1
Setting
prohibited
−
10 to 8
FR2 to
FR0
Note
This is the time from sampling until conversion end.
Sampling time = (Conversion clocks
−
8)/6
×
f
XX
Caution
Be sure to secure the conversion time within a range of 5 to
10
µ
s.
Conversion time = f
XX
×
Conversion clocks
Remark
f
XX
: Internal system clock
