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Rev. 1.00
193 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
12
Analog to Digital Converter (ADC)
12
Analog to Digital Converter (ADC)
Discontinuous Conversion Mode
(ex: Sequence Length=8, Subgroup Length=3 )
CH2
Cycle
Start of
Conversion
CH4
CH7
CH5
CH6
CH3
CH0
CH1
Subgroup End
of Conversion
CH2
CH4
CH7
Subgroup 0
Subgroup 1
Subgroup 2
Subgroup 0
Cycle End of
Conversion
Single sample
End of
Conversion
Cycle
Figure 33. Discontinuous Conversion Mode
Start Conversion on External Event
An A/D conversion can be initiated by a software trigger, a comparator output transition event, a
General-Purpose Timer Module (GPTM) event, a Motor Control Timer Module (MCTM) event,
a Basic Function Timer Module (BFTM) event or an external trigger. Each trigger source can be
enabled by setting the corresponding enable control bit in the ADCTCR register and then selected
by configuring the associated selection bits in the ADCTSR register to start a group channel
conversion.
An A/D converter conversion can be started by setting the software trigger bit, ADSC, in the
ADCTSR register for the group channel when the software trigger enable bit, ADSW, in the
ADCTCR register is set to 1. After the A/D converter starts converting the analog data, the
corresponding enable bit ADSC will be cleared to 0 automatically.
The A/D converter can also be triggered to start a group conversion by a TM event. The TM events
include a GPTM or MCTM master trigger output MTO, four GPTM or MCTM channel outputs
CH0 ~ CH3 and a BFTM trigger output. If the corresponding Timer trigger enable bit is set to 1
and the trigger output or the TM channel event is selected via the relevant TM event selection bits,
the A/D converter will start a conversion when a rising edge of the selected trigger event occurs.
In addition to the internal trigger sources, the A/D converter can be triggered to start a conversion
by an external trigger event. The external trigger event is derived from the external lines, EXTIn.
If the external trigger enable bit ADEXTI is set to 1 and the corresponding EXTI line is selected by
configuring the ADEXTIS field in the ADCTSR register, the A/D converter will start a conversion
when an EXTI line active edge determined in the EXTI Unit occurs.