Operation Under Group Priority Control - Renesas RX100 Series User Manual

RX13T Group
26.3.4.3

Operation under Group Priority Control

Setting the ADGSPCR.PGS bit to 1 in group scan mode makes operation proceed under group priority control. The
group priority order is group A > group B > group C. Either two (groups A and B) or three (groups A, B, and C) can be
selected as the number of the groups to be used in group scan mode. When setting the ADGSPCR.PGS bit to 1, follow
the procedure described in Figure 26.15 . If the procedure is not followed, proper scanning operation and data storage
are not guaranteed.
In basic operation of group scan mode, if group A, B, or C is scanning, all other trigger inputs are ignored. Under group
priority control, if a priority group trigger is input during A/D conversion for the low-priority group, A/D conversion for
the low-priority group is discontinued and A/D conversion for the priority group proceeds.
If the ADGSPCR.GBRSCN bit is 0, the converter enters a wait state for the low-priority group on completion of the A/D
conversion for the priority group.
The trigger input for the low-priority group during scanning is ignored.
If the ADGSPCR.GBRSCN bit is 1, the converter automatically restarts scanning for the low-priority group from the
head of the group after A/D conversion for the priority group.
Also, the trigger input for the low-priority group generated during scanning for the priority group is enabled, and the
converter automatically restarts scanning for the low-priority group after scanning for the priority group.
When the ADGSPCR.LGRRS bit is 0 while the ADGSPCR.GBRSCN bit is 1, the converter restarts scanning for the
low-priority group from the head of the group. When the ADGSPCR.LGRRS bit is 1, the converter restarts scanning for
the low-priority group from the channel on which scanning is discontinued.
However, when self-diagnosis is used, the converter restarts scanning from the channel on which scanning is
discontinued after self-diagnosis is completed.
Table 26.10 summarizes operations in response to the input of a trigger during scanning with the settings of the
ADGSPCR.GBRSCN bit.
When the ADGSPCR.GBRP bit is set to 1, scan operations in the lowest-priority group are continuously performed.
For the trigger settings in group scan mode, select a synchronous trigger for group A using the ADSTRGR.TRSA[5:0]
bits, select a synchronous trigger different from that of group A for group B using the ADSTRGR.TRSB[5:0] bits, and
select a synchronous trigger different from those of groups A and B for group C using the ADGCTRGR.TRSC[5:0] bits.
Set the ADSTRGR.TRSB[5:0] bits to 3Fh when setting group scan mode for two groups (the ADGCTRGR.GRCE bit to
0) and setting the ADGSPCR.GBRP bit to 1.
Set the ADGCTRGR.TRSC[5:0] bits to 3Fh when setting group scan mode for three groups (the ADGCTRGR.GRCE bit
to 1) and setting the ADGSPCR.GBRP bit to 1.
Furthermore, as targets for scanning, select channels for group A using the ADANSA0 register, select channels for group
B using the ADANSB0 register, and select channels for group C using the ADANSC0 register.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
26. 12-Bit A/D Converter (S12ADF)
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