XMC4500: ADC: sync conversions

[jsmith678x]

Hi,

I'm studying the DAVE Help/VADC_GROUP_CONFIG app manual/Example to illustrate synchronous conversions. 

It is not clear which is the second channel. The example talks about Channel 2 of some group but I think we need an another channel to measure also. Which channel will be the second channel to be measured?

[Vasanth]

Hi,

Kindly check this appnote section on synchronous conversion and examples.

Best Regards,
Vasanth

[Vasanth · Accepted solution]

Hi,

I think I can give some more clarity. Synchronization in the XMC4XXX VADC works with a master-slave concept. When the master starts a synchronous conversion, the slaves cancel the actual conversion and respond with a ready signal. When the master and the slaves are ready the conversion is started. After this conversion the slaves inject and repeat the canceled conversion.

The synchronous conversion has some constrains. The channel number from master and the slaves are the same. For example, if the master requests channel 5 the synchronous slave channel is also converting channel 5. This limit of free pin mapping can be solved with the ALIAS feature (check for Programmable Remapping of Analog Inputs – The Alias Feature).

Now in the associated code example the channels 1 and 0 of group 1 are converted at the same time as channel 1 and 0 of group 0. The channels are configured as refill so the queue will be fed again with these channels after each conversion.

Best Regards,
Vasanth