GD32F403xx User Manual
195
Software procedure for single operation mode of a routine channel:
1.
Make sure the DISRC, SM in the ADC_CTL0 register and CTN bit in the ADC_CTL1
register are reset.
2.
Conf igure RSQ0 with the analog channel number.
3.
Conf igure ADC_SAMPTx register.
4.
Conf igure ETERC and ETSRC bits in the ADC_CTL1 register if in need .
5.
Set the SWRCST bit, or generate an external trigger for the
routine sequence.
6.
Wait the EOC f lag to be set.
7.
Read the converted data in the ADC_RDATA register.
8.
Clear the EOC f lag 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 external trigger is active. The conversion data will be
stored in the ADC_RDATA register.
Figure 12-3. Continuous operation mode
CH2
CH2
CH2
CH2
CH2
CH2
EOC
Routine
trigger
Sample
Convert
CH2
Sof tware procedure for continuous operation on a
routine channel:
1.
Set the CTN bit in the ADC_CTL1 register.
2.
Conf igure RSQ0 with the analog channel number.
3.
Conf igure ADC_SAMPTx register.
4.
Conf igure ETERC and ETSRC bits in the ADC_CTL1 register if in need .
5.
Set the SWRCST bit, or generate an external trigger for the
routine sequence.
6.
Wait the EOC f lag to be set.
7.
Read the converted data in the ADC_RDATA register.
8.
Clear the EOC f lag 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.
Conf igure RSQ0 with the analog channel number.
3.
Conf igure ADC_SAMPTx register.
4.
Conf igure 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 an external trigger for the
routine sequence.