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Rev. 1.00
166 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
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 29. Discontinuous Conversion Mode
Start Conversion on External Event
An A/D converter conversion can be initiated by a software trigger, a General-Purpose Timer
Module (GPTM) event, a Motor Control Timer Module (MCTM) event, a PWM Trigger 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 Timer event. The Timer
events include a PWM master trigger output MTO, four PWM channel outputs CH0 ~ CH3, 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 Timer channel event is selected via the relevant Timer 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 of the
EXTI unit. 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 activity occurs.