It is mentioned in the datasheet that one can use an analog multiplexer in the enCoRe III part but I do not see a user module for the same. How to use this multiplexer?
Unfortunately, we do not have a user module for the analog multiplexer in enCoRe III parts. But, you can still use this with the help of registers directly. Detailed information on analog multiplexer registers is provided in the PSoC Technical Reference Manual.