R01UH0823EJ0100 Rev.1.00
Page 1540 of 1823
Jul 31, 2019
RX23W Group
44. 12-Bit A/D Converter (S12ADE)
is set to 1 as long as the scan is started by the synchronous trigger selected by the ADSTRGR.TRSA[5:0] bits.
ADCS[1:0] Bits (Scan Mode Select)
The ADCS[1:0] bits select the scan mode.
In single scan mode, A/D conversion is performed for the analog inputs of a maximum of 14 channels selected with the
ADANSA0 and ADANSA1 registers in the ascending order of the channel number, and when one cycle of A/D
conversion is completed for all the selected channels, the scan conversion is stopped.
In continuous scan mode, while the ADCSR.ADST bit is 1, A/D conversion is performed for the analog inputs of a
maximum of 14 channels selected with the ADANSA0 and ADANSA1 registers in the ascending order of the channel
number, and when one cycle of A/D conversion is completed for all the selected channels, A/D conversion is repeated
from the first channel. If the ADCSR.ADST bit is set to 0 during continuous scan, A/D conversion is stopped even if
scanning is in progress.
In group scan mode, A/D conversion is performed for the analog inputs (group A) of 14 channels selected with the
ADANSA0 and ADANSA1 registers in the ascending order of the channel number after scanning is started by the
synchronous trigger selected by the ADSTRGR.TRSA[5:0] bits, and when one cycle of A/D conversion is completed for
all the selected channels, A/D conversion is stopped. A/D conversion is also performed for the analog inputs (group B) of
a maximum of 14 channels selected with the ADANSB0 and ADANSB1 registers in the ascending order of the channel
number after scanning is started by the synchronous trigger selected by the ADSTRGR.TRSB[5:0] bits, and when one
cycle of A/D conversion is completed for all the selected channels, A/D conversion is stopped.
When selecting group scan mode, different channels and triggers should be selected for group A and group B.
When selecting the temperature sensor output or internal reference voltage, select single scan mode, and deselect all the
channels selected with the ADANSA0 and ADANSA1 registers before performing A/D conversion. When A/D
conversion of the selected temperature sensor output or internal reference voltage is completed, A/D conversion is
stopped.
The ADCS[1:0] bits should be set while the ADST bit is 0. They should not be set simultaneously when 1 is written to
the ADST bit.
ADST Bit (A/D Conversion Start)
The ADST bit starts or stops A/D conversion process.
Before the ADST bit is set to 1, set the A/D conversion clock, the conversion mode, and conversion target analog input.
[Setting conditions]
1 is written by software.
The synchronous trigger selected by the ADSTRGR.TRSA[5:0] bits is detected with ADCSR.EXTRG and
ADCSR.TRGE bits being set to 0 and 1, respectively.
The synchronous trigger selected by the ADSTRGR.TRSB[5:0] bits is detected with the ADCSR.TRGE bit being
set to 1 in group scan mode.
The asynchronous trigger is detected with the ADCSR.TRGE and ADCSR.EXTRG bits being set to 1 and the
ADSTRGR.TRSA[5:0] bits being set to 000000b.
With group-A priority control operation mode enabled (ADCSR.ADCS[1:0] bits = 01b and ADGSPCR.PGS bit =
1), a group B trigger is detected and A/D conversion of group B is started.
With group-A priority control operation mode enabled (ADCSR.ADCS[1:0] bits = 01b and ADGSPCR.PGS bit =
1), the ADGSPCR.GBRSCN bit is set to 1 and A/D conversion of group B is restarted.
With group-A priority control operation mode enabled (ADCSR.ADCS[1:0] bits = 01b and ADGSPCR.PGS bit =
1), the ADGSPCR.GBRP bit is set to 1 and A/D conversion of group B is started.
[Clearing conditions]
0 is written by software.
The A/D conversion of all the selected channels, the temperature sensor output, or the internal reference voltage is
completed in single scan mode.