GD32A50x User Manual
271
3.
Configure ADC_SAMPTx register.
4.
Configure ETERC and ETSRC bits in the ADC_CTL1 register if in need.
5.
Set the SWRCST bit, or generate a
TRIGSEL trigger for the routine sequence.
6.
Wait the EOC flag to be set.
7.
Read the converted date in the ADC_RDATA register.
8.
Clear the EOC flag by writing 0 to it.
Continuous operation mode
The continuous operation mode will be enabled when CTN bit in the ADC_CTL1 register is
set. In this mode, the ADC performs conversion on the channel specified in the RSQ0[4:0].
When the ADCON has been set high, the ADC samples and converts specified channel, once
the corresponding software trigger or TRIGSEL trigger is active. The conversion data will be
stored in the ADC_RDATA register.
Figure 14-3. Continuous operation mode
CH2
CH2
CH2
CH2
CH2
CH2
EOC
Routine
trigger
Sample
Convert
CH2
Software procedure for continuous
operation mode on a routine channel:
1.
Set the CTN bit in the ADC_CTL1 register.
2.
Configure RSQ0 with the analog channel number.
3.
Configure ADC_SAMPTx register.
4.
Configure ETERC and ETSRC bits in the ADC_CTL1 register if in need.
5.
Set the SWRCST bit, or generate a
TRIGSEL
trigger for the routine sequence.
6.
Wait the EOC flag to be set.
7.
Read the converted date in the ADC_RDATA register.
8.
Clear the EOC flag by writing 0 to it.
9.
Repeat steps 6~8 as soon as the conversion is in need.
To get rid of checking, DMA can be used to transfer the converted data:
1.
Set the CTN and DMA bit in the ADC_CTL1 register.
2.
Configure RSQ0 with the analog channel number.
3.
Configure ADC_SAMPTx register.
4.
Configure ETERC and ETSRC bits in the ADC_CTL1 register if in need.
5.
Prepare the DMA module to transfer data from the ADC_RDATA.
6.
Set the SWRCST bit, or generate a
TRIGSEL trigger for the routine sequence.
Scan operation mode
The scan operation mode will be enabled when SM bit in the ADC_CTL0 register is set. In
this mode, the ADC performs conversion on all channels with a specific routine sequence
specified in the ADC_RSQ0~ADC_RSQ2 registers. When the ADCON has been set high, the
ADC samples and converts specified channels one by one in the routine sequence till the end