Overview - Renesas RX100 Series User Manual

RX13T Group
26. 12-Bit A/D Converter (S12ADF)
In this section, "PCLK" is used to refer to PCLKB.
26.1

Overview

This MCU incorporates one unit of a 12-bit successive approximation A/D converter. The one A/D converter unit (unit
0) provides eight channels for use, and the analog inputs and internal reference voltage for the converter are selectable.
The 12-bit A/D converter converts a maximum of eight selected channels of analog inputs and internal reference voltage
into a 12-bit digital value through successive approximation.
The A/D converter has three operating modes: single scan mode in which the analog inputs of eight channels are
converted in ascending channel order; continuous scan mode in which the analog inputs of eight channels are
continuously converted in ascending channel order; and group scan mode in which eight channels are arbitrarily divided
into two groups (groups A and B) or three groups (groups A, B, and C) and converted in ascending channel order in each
group.
In group scan mode, either two groups (groups A and B) or three groups (groups A, B, and C) is selected.
The conditions for scanning start of each group (A and B or A, B, and C) (synchronous trigger) can be independently
selected, thus allowing A/D conversion of each group to be started independently.
During group priority operation, in addition to the above-mentioned operation, a trigger to start scanning for the priority
group is accepted during scan for the low-priority group, and scan for the priority group is started after scan for the low-
priority group was discontinued. The priority order is group A > group B > group C. Accordingly, as priority operation,
when a trigger to start scanning for group B is accepted during scan for group C, group C scan is discontinued, and scan
for group B is started. Likewise, when a trigger to start scanning for group A is accepted during scan for group C, group
C scan is discontinued and scan for group A is started. In the same way, when a trigger to start scanning for group A is
accepted during scan for group B, group B scan is discontinued and scan for group A is started.
The discontinued scan operation can be restarted after the scanning of the priority group is completed.
In double trigger mode, one analog input channel arbitrarily selected is converted in single scan mode or group scan
mode (group A), and the resulting data of A/D conversion started by the first and second synchronous triggers are stored
into different registers (duplication of A/D conversion data).
Self-diagnosis is executed once at the beginning of each scan, and one of the three voltages internally generated in the
12-bit A/D converter is converted.
Table 26.1 lists the specifications of the 12-bit A/D converter and Table 26.2 lists the functions of the 12-bit A/D
converter. Figure 26.1 shows block diagrams of the 12-bit A/D converter.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
26. 12-Bit A/D Converter (S12ADF)
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