![Renesas RX Series Скачать руководство пользователя страница 1530](http://html.mh-extra.com/html/renesas/rx-series/rx-series_user-manual_14404901530.webp)
R01UH0823EJ0100 Rev.1.00
Page 1530 of 1823
Jul 31, 2019
RX23W Group
44. 12-Bit A/D Converter (S12ADE)
44.
12-Bit A/D Converter (S12ADE)
In this section, “PCLK” is used to refer to PCLKB.
44.1
Overview
This MCU incorporates one unit of a 12-bit successive approximation A/D converter. Up to 14 channel analog inputs,
temperature sensor output, and internal reference voltage are selectable for conversion.
The 12-bit A/D converter converts a maximum of 14 selected channels of analog inputs, temperature sensor output, and
internal reference voltage, which have been selected, 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 up to 14 arbitrarily
selected channels are converted only once in ascending channel order; and continuous scan mode in which the analog
inputs of up to 14 arbitrarily selected channels are continuously converted in ascending channel order; and group scan
mode in which up to 14 channels of the analog inputs are arbitrarily divided into two groups (group A and group B) and
converted in ascending channel order in each group.
In group scan mode, the conditions for scanning start of group A and group B (synchronous trigger) can be
independently selected, thus allowing A/D conversion of group A and group B to be started independently. When group-
A priority control is selected along with operation as described above, if a request to start scanning for group A is
received during A/D conversion for group B, the conversion operation for group B is discontinued and the conversion for
group A starts, which is given priority.
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.
It is prohibited to simultaneously select both temperature sensor output and internal reference voltage. Perform A/D
conversion independently for the temperature sensor output or the internal reference voltage.
The external pin input (VREFH0) or the analog reference voltage (AVCC0) is selectable as the reference voltage on the
high-potential side. The external pin input (VREFL0) or the analog reference voltage (AVSS0) is selectable as the
reference voltage on the low-potential side.
This IP has a compare function (window A and window B). This function is used to specify the high-side reference value
and low-side reference value for window A and window B, respectively. When the A/D-converted value of the selected
channel meets the comparison conditions, the ELC event (S12ADWMELC/S12ADWUMELC) is output according to
the event conditions (A or B, A and B, A exor B). Furthermore, the comparator operation to compare the A/D-converted
value with the low-side reference value is also enabled.
The A/D data storage buffer is a ring buffer consisting of 16 buffers to sequentially store A/D converted data.
lists the specifications of the 12-bit A/D converter and
lists the functions of the 12-bit A/D
converter.
shows a block diagram of the 12-bit A/D converter.