Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
A-D Converter
157
(2) Repeat mode
I
n repeat mode, the pin selected using the analog input pin select bit is used for repeated A-D conversion.
Table 1.20.3 shows the specifications of repeat mode. Figure 1.20.5 shows the A-D control register in
repeat mode.
A-D control register 0 (Note 1)
Symbol
ADCON0
Address
03D6
16
When reset
00000XXX
2
b7
b6
b5
b4
0
b3
1
b2
b1
b0
Analog input pin
select bit
CH0
Bit symbol
Bit name
Function
CH1
CH2
A-D operation mode
select bit 0
MD0
MD1
Trigger select bit
0 : Software trigger
1 : AD
TRG
trigger
0 : A-D conversion disabled
1 : A-D conversion started
TRG
ADST
A-D conversion start flag
Frequency select bit 0
0 : f
AD
/4 is selected
1 : f
AD
/2 is selected
CKS0
W
R
A-D control register 1 (Note)
Symbol
ADCON1
Address
03D7
16
When reset
00
16
Bit name
Function
Bit symbol
b7
b6
b5
1
b4
b3
b2
0
b1
b0
A-D sweep pin
select bit
SCAN0
SCAN1
MD2
BITS
8/10-bit mode select bit
0 : 8-bit mode
1 : 10-bit mode
0 : f
AD
/2 or f
AD
/4 is selected
1 : f
AD
is selected
VCUT
OPA0
Vref connect bit
OPA1
A-D operation mode
select bit 1
1 : Vref connected
External op-amp
connection mode bit
W
R
Invalid in repeat mode
0 0 0 : AN
0
is selected
0 0 1 : AN
1
is selected
0 1 0 : AN
2
is selected
0 1 1 : AN
3
is selected
1 0 0 : AN
4
is selected
1 0 1 : AN
5
is selected
1 1 0 : AN
6
is selected
1 1 1 : AN
7
is selected
(Note 2)
b2 b1 b0
0 1 : Repeat mode
(Note 2)
b4 b3
0 0 : ANEX0 and ANEX1 are not used
0 1 : ANEX0 input is A-D converted
1 0 : ANEX1 input is A-D converted
1 1 : External op-amp connection mode
Note 1: If the A-D control register is rewritten during A-D conversion, the conversion
result is indeterminate.
Note 2: When changing A-D operation mode, set analog input pin again.
Frequency select bit 1
CKS1
0 : Any mode other than repeat sweep mode 1
Note: If the A-D control register is rewritten during A-D conversion, the conversion
result is indeterminate.
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
A
Figure 1.20.5. A-D conversion register in repeat mode
Item
Specification
Function
Star condition
Stop condition
Interrupt request generation timing
Input pin
Reading of result of A-D converter
The pin selected by the analog input pin select bit is used for repeated A-D conversion
Writing “1” to A-D conversion start flag
Writing “0” to A-D conversion start flag
None generated
One of AN
0
to AN
7
, as selected
Read A-D register corresponding to selected pin
Table 1.20.3. Repeat mode specifications