Renesas M32R/ECU Series, User Manual

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11
11-21
A-D Converters
32180 Group User's Manual (Rev.1.0)
11.2 A-D Converter Related Registers
(2) ADCMSL (A-D Scan Mode Select) bit (Bit 1)
This bit selects scan mode of the A-D Converter between single-shot scan and continuous scan.
Setting this bit to "0" selects single-shot scan mode, where the channels selected with the ANSCAN (scan
loop select) bits are sequentially A-D converted and when A-D conversion on all selected channels is com-
pleted, the conversion operation stops.
Setting this bit to "1" selects continuous scan mode, where after operation in single-shot scan mode finishes,
A-D conversion is reexecuted beginning with the first channel and continued until stopped by setting the
ADCSTP (A-D conversion stop) bit to "1".
(3) ADCSEL (A-D Conversion Start Trigger Select) bit (Bit 3)
This bit selects whether to use a software or hardware trigger to start A-D conversion during scan mode. If a
software trigger is selected, A-D conversion is started by setting the ADCSTT (A-D conversion start) bit to
"1". If a hardware trigger is selected, A-D conversion is started by the trigger source selected with the
ADnCTRG (hardware trigger select) bits.
(4) ADCREQ (A-D Interrupt/DMA Transfer Request Select) bit (Bit 4)
This bit selects whether to request an A-D conversion interrupt or a DMA transfer when one cycle of scan
mode operation is completed. If neither an interrupt nor a DMA transfer are used, choose to request an A-D
conversion interrupt and use the A-D Converter Interrupt Control Register of the Interrupt Controller (ICU) to
mask the interrupt request, or choose to request a DMA transfer and use the DMA Channel Control Register
to disable DMA transfers to be performed upon completion of A-D conversion.
(5) ADCCMP (A-D Conversion Completed) bit (Bit 5)
This is a read-only bit, whose value after reset is 1. This bit is 0 when the A-D Converter is performing scan
mode A-D conversion and is set to "1" when single-shot scan mode finishes or continuous scan mode is
stopped by setting the ADCSTP (A-D conversion stop) bit to "1".
(6) ADCSTP (A-D Conversion Stop) bit (Bit 6)
Setting this bit to "1" while the A-D Converter is performing scan mode A-D conversion causes the operation
being performed to stop. This bit is effective only for scan mode operation, and does not affect single mode
operation even when single and scan modes both are active during special operation mode.
Operation stops immediately after writing to this bit, and the A-D conversion being performed on any channel
is aborted in the middle, without transferring the result to the A-D data register.
If the A-D conversion start bit and A-D conversion stop bit are set to "1" at the same time, the A-D conversion
stop bit has priority.
(7) ADCSTT (A-D Conversion Start) bit (Bit 7)
This bit is used to start scan mode operation of the A-D Converter in software. Only when a software trigger
has been selected with the ADCSEL (A-D conversion start trigger select) bit, setting this bit to "1" causes A-
D conversion to start.
If the A-D conversion start bit and A-D conversion stop bit are set to "1" at the same time, the A-D conversion
stop bit has priority.
If this bit is set to "1" again while performing scan mode conversion, special operation mode “Conversion
restart” is turned on, so that scan mode operation is restarted using the contents set by A-D Scan Mode
Registers 0 and 1.
If this bit is set to "1" again while performing A-D conversion in scan mode, special operation mode “Scan
mode start after single mode execution” is turned on, so that scan mode operation starts subsequently after
single mode has finished.