M16C62_M Datasheet, PDF (443/615 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
2.7.7 Operation of A-D Converter (in single sweep mode)
In single sweep mode, choose functions from those listed in Table 2.7.7. Operations of the circled items
are described below. Figure 2.7.15 shows timing chart, and Figure 2.7.16 shows the set-up procedure.
Table 2.7.7. Choosed functions
Item
Set-up
Item
Set-up
Operation clock AD
Resolution
Analog input pin
O
Divided-by-4 fAD / divided-
by-2 fAD / fAD
Trigger for starting A- O Software trigger
D conversion
Trigger by ADTRG
O 8-bit / 10-bit
Expanded analog
input pin
AN0 and AN1 (2 pins) / AN0
O to AN3 (4 pins) / AN0 to AN5
(6 pins) / AN0 to AN7 (8 pins) Sample & Hold
O Not used
External ope-amp
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 AN0 pin.
(2) After the A-D conversion of voltage input to the AN0 pin is completed, the content of the
successive comparison register (conversion result) is transmitted to A-D register 0. The A-D
converter converts all analog input pins selected by the user. The conversion result is trans-
mitted to A-D register i corresponding to each pin, every time conversion on one pin is com-
pleted.
(3) When the A-D conversion on all the analog input pins selected is completed, the A-D conver-
sion interrupt request bit goes to “1”. At this time, the A-D conversion start flag goes to “0”.
The A-D converter stops operating.
(1) Start A-D conversion
(2) _{After A-D conversion on AN0 pin is complete,}
A-D converter begins converting all pins selected
8-bit resolution : 28 φAD cycles 8-bit resolution : 28 φAD cycles
10-bit resolution : 33 φAD cycles 10-bit resolution : 33 φAD cycles
φAD
A-D conversion _{“1”}
start flag
“0”
A-D register 0
A-D register 1
Set to “1” by software
Result
Result
(3) _{A-D conversion}
is complete
A-D register i
Result
A-D conversion “1”
interrupt request
bit
“0”
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 2.7.15. Operation timing of single sweep mode
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