Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
A-D Converter
123
Item
Specification
Function
All pins perform repeat sweep A-D conversion, with emphasis on the pin or
pins selected by the A-D sweep pin select bit
Example : AN
0
selected AN
0
AN
1
AN
0
AN
2
AN
0
AN
3
, etc
Writing “1” to A-D conversion start flag
Writing “0” to A-D conversion start flag
None generated
AN
0
(1 pin), AN
0
and AN
1
(2 pins), AN
0
to AN
2
(3 pins), AN
0
to AN
3
(4 pins)
Read A-D register corresponding to selected pin (at any time)
Start condition
Stop condition
Interrupt request generation timing
Input pin
Reading of result of A-D converter
(5) Repeat sweep mode 1
In repeat sweep mode 1, all pins are used for A-D conversion with emphasis on the pin or pins selected
using the A-D sweep pin select bit. Table 1.18.6 shows the specifications of repeat sweep mode 1. Figure
1.18.8 shows the A-D control register in repeat sweep mode 1.
A-D control register 0 (Note)
Symbol
ADCON0
Address
03D6
16
When reset
00000XXX
2
b7
b6
b5
b4
1 1
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 1 : Repeat sweep mode 1
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
1
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
1 : Repeat sweep mode 1
OPA1
A-D operation mode
select bit 1
1 : Vref connected
External op-amp
connection mode
bit (Note 2)
Invalid in repeat sweep mode 1
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 repeat sweep mode 1 is selected
0 0 : AN
0
(1 pin)
0 1 : AN
0
, AN
1
(2 pins)
1 0 : AN
0
to AN
2
(3 pins)
1 1 : AN
0
to AN
3
(4 pins)
b1 b0
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
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
Figure 1.18.8. A-D conversion register in repeat sweep mode 1
Table 1.18.6. Repeat sweep mode 1 specifications