R01UH0823EJ0100 Rev.1.00
Page 1591 of 1823
Jul 31, 2019
RX23W Group
44. 12-Bit A/D Converter (S12ADE)
44.3.4
Group Scan Mode
44.3.4.1
Basic Operation
In basic operation of group scan mode, A/D conversion is performed once on the analog inputs of all the specified
channels in group A and group B after scanning is started by a synchronous trigger as below. Scan operation of each
group is similar to the scan operation in single scan mode.
The synchronous triggers of group A and B can be selected using the TRSA[5:0] and TRSB[5:0] bits in ADSTRGR,
respectively. The different triggers should be used for group A and group B to prevent simultaneous A/D conversion of
group A and group B. Software trigger should not be used.
The group A channels to be A/D-converted are selected using the ADANSA0 and ADANSA1 registers while the group
B channels to be A/D-converted are selected using the ADANSB0 and ADANSB1 registers. The same channels cannot
be selected for both groups.
In group scan mode, the temperature sensor output A/D conversion select bit (ADEXICR.TSSA) and the internal
reference voltage A/D conversion select bit (ADEXICR.OCSA) should be set to 0 (deselected).
When self-diagnosis is selected in group scan mode, self-diagnosis is separately executed for group A and group B.
The following describes operation in group scan mode using a trigger from the MTU. The TRG4AN and TRG4BN
triggers from the MTU are assumed to be used to start conversion of group A and group B, respectively.
(1) Scanning of group A is started by the TRG4AN trigger from the MTU.
(2) When group A scanning is completed, an S12ADI0 interrupt is generated if the ADCSR.ADIE bit is 1 (S12ADI0
interrupt upon scanning completion enabled).
(3) Scanning of group B is started by the TRG4BN trigger from the MTU.
(4) When group B scanning is completed, a GBADI interrupt is generated if the ADCSR.GBADIE bit is 1 (GBADI
interrupt upon scanning completion enabled).
Figure 44.11
Example of Operation in Group Scan Mode
(Basic Operation: Synchronous Triggers from MTU Used)
TRG4AN event
TRG4BN event
TRG4AN
TRG4BN
Group A scanned
Group B scanned
GBADI interrupt
Timer count
(1)
(2)
(3)
(4)
Time
S12ADI0
interrupt