152
Mitsubishi microcomputers
M16C / 62T Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
A-D Converter
(1) One-shot mode
In one-shot mode, the pin selected using the analog input pin select bit is used for one-shot A-D conver-
sion. Table 1.20.2 shows the specifications of one-shot mode. Figure 1.20.4 shows the A-D control regis-
ter in one-shot mode.
Table 1.20.2. One-shot mode specifications
Figure 1.20.4. A-D conversion register in one-shot mode
A-D control register 0 (Note 1)
Symbol
Address
When reset
ADCON0
03D616
00000XXX2
b7
b6
b5
b4
b3
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 : ADTRG trigger
TRG
ADST
A-D conversion start flag
0 : A-D conversion disabled
1 : A-D conversion started
Frequency select bit 0
0 : fAD/4 is selected
1 : fAD/2 is selected
CKS0
W
R
A-D control register 1 (Note 1)
Symbol
Address
When reset
ADCON1
03D716
0016
Bit name
Function
Bit symbol
b7
b6
b5
b4
b3
b2
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
VCUT
OPA0
Vref connect bit
OPA1
A-D operation mode
select bit 1
1 : Vref connected
External op-amp
connection mode bit
W
R
00
Invalid in one-shot mode
0
0 0 0 : AN0 is selected
0 0 1 : AN1 is selected
0 1 0 : AN2 is selected
0 1 1 : AN3 is selected
1 0 0 : AN4 is selected
1 0 1 : AN5 is selected
1 1 0 : AN6 is selected
(Note 2)
1 1 1 : AN7 is selected
(Note 3)
b2 b1 b0
0 0 : One-shot mode
(Note 3)
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
b7 b6
1
Note 1: If the A-D control register is rewritten during A-D conversion, the conversion
result is indeterminate.
Note 2: AN00 to AN07, and AN20 to AN27 can be used the same as AN0 to AN7.
Note 3: When changing A-D operation mode, set analog input pin again.
Frequency select bit 1
0 : fAD/2 or fAD/4 is selected
1 : fAD is selected
CKS1
0 : Any mode other than 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: Divide the frequency if f(XIN) exceeds 10MHz, and make
φAD frequency
equal to 10MHz.
(Note 2)
Item
Specification
Function
The pin selected by the analog input pin select bit is used for one A-D conversion
Start condition
Writing “1” to A-D conversion 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
One of AN0 to AN7, as selected
(Note 1)
Reading of result of A-D converter
Read A-D register corresponding to selected pin
Note 1: AN00 to AN07, and AN20 to AN27 can be used the same as AN0 to AN7.