Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
A-D Converter
121
(3) Single sweep mode
I
n single sweep mode, the pins selected using the A-D sweep pin select bit are used for one-by-one A-D
conversion. Table 1.18.4 shows the specifications of single sweep mode. Figure 1.18.6 shows the A-D
control register in single sweep mode.
Table 1.18.4. Single sweep mode specifications
Item
Function
The pins selected by the A-D sweep pin select bit are used for one-by-one A-D conversion
Start condition
Writing “1” to A-D converter start flag
Stop condition
End of A-D conversion (A-D conversion start flag changes to “0”, except
when external trigger is selected)
Writing “0” to A-D conversion start flag
Interrupt request generation timing
End of A-D conversion
Input pin
AN
0
and AN
1
(2 pins), AN
0
to AN
3
(4 pins), AN
0
to AN
5
(6 pins), or AN
0
to AN
7
(8 pins)
Reading of result of A-D converter
Read A-D register corresponding to selected pin
Figure 1.18.6. A-D conversion register in single sweep mode
A-D control register 0 (Note)
Symbol
ADCON0
Address
03D6
16
When reset
00000XXX
2
b7
b6
b5
b4
1 0
b3
b2
b1
b0
Analog input pin
select bit
CH0
Bit symbol
Bit name
Function
CH1
CH2
A-D operation mode
select bit 0
1 0 : Single sweep mode
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 1)
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
0 : Any mode other than repeat sweep mode 1
OPA1
A-D operation mode
select bit 1
1 : Vref connected
External op-amp
connection mode
bit (Note 2)
W
R
Invalid in single sweep mode
Note 1: If the A-D control register is rewritten during A-D conversion, the conversion result
is indeterminate.
Note 2: Neither ‘01’ nor ‘10’ can be selected with the external op-amp connection mode bit.
b4 b3
When single sweep and repeat sweep mode 0
are selected
b1 b0
0
, AN
1
(2 pins)
0 1 : AN
0
to AN
3
(4 pins)
1 0 : AN
0
to AN
5
(6 pins)
1 1 : AN
0
to AN
7
(8 pins)
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
b7 b6
Note: If the A-D control register is rewritten during A-D conversion, the conversion result
is indeterminate.
Frequency select bit 1
CKS1
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
Specification