M16C62_M Datasheet, PDF (437/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

A-D Converter
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.7.4 Operation of A-D Converter (in one-shot mode, expanded analog input pin selected)
In one-shot mode, choose functions from those listed in Table 2.7.4. Operations of the circled items
are described below. Figure 2.7.9 shows timing chart, and Figure 2.7.10 shows the set-up procedure.
Table 2.7.4. Choosed functions
Item
Operation clock
φAD
Set-up
O
Divided-by-4 fAD / divided-
by-2 fAD / fAD
Resolution
Analog input pin
Trigger for starting
A-D conversion
O 8-bit / 10-bit
O One of AN0 pin to AN7 pin
O Software trigger
Trigger by ADTRG
Item
Expanded analog
input pin
Sample & Hold
Set-up
Not used
O
Either ANEX0 pin or
ANEX1 pin
External operation amplifier
connection mode
Not activated
O Activated
Operation (1) Setting the A-D conversion start flag to “1” causes the A-D converter to start the conversion on
voltage input to the ANEXi pin.
(2) After the A-D conversion of voltage input to the ANEXi pin is completed, the content of the
successive comparison register (conversion result) is transmitted to the A-D register. At the
same time, the A-D conversion interrupt request bit goes to “1”. Also, the A-D conversion start
flag goes to “0”, and the A-D converter stops operating.
φAD
A-D conversion ^{“1”}
start flag
“0”
A-D register i
A-D conversion ^{“1”}
interrupt request _{“0”}
(1) Start A-D conversion
8-bit resolution : 28 φAD cycles
10-bit resolution : 33 φAD cycles
(2) A-D convesion is complete
Set to “1” by software
Result
Cleared to “0” when interrupt request is accepted, or cleared by software
Note: When φAD frequency is less than 1MHZ, sample and hold function cannot be selected.
Conversion rate per analog input pin is 49 φAD cycles for 8-bit resolution and 59 φAD cycles for 10-bit resolution.
Figure 2.7.9. Operation timing of one-shot mode, with expanded analog input pin selected
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