Mixed single-ended/differential ADC and the limits of AMUX

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PiWy_2406846
Level 3
Level 3

Hello,

   

I have 8 analog channels to monitor, 6 of them are differential (the minus ADC input is then at +2.5V) and the remaining 2 single-ended. I think the single-ended channels can be simulated using VSSA as the input. I'm curious whether the SAR ADC can be dynamically reconfigured in flight, but it is not the main issue. It seems that the hardware analog MUX cannot map the same input pin to many of its channels. The VSSA reference has also been refused. Since a picture is worth a thousand words, the first image shows what I wanted, the second shows what the tool can swallow. Does the second diagram conform to the common PSOC sanity rules, or should I change something?

   

In both cases the MUX index generator is just a mockup, I know it is technically incorrect.

   

    Best regards

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

When you use the Sequencing SAR component you can configure it exactly for your needs. Use latest Creator 4.0 SP1

   

 

   

Bob

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PiWy_2406846
Level 3
Level 3

Hmm, it doesn't seem to solve any of my problems: it can't have the same analog IO pin connected to many of its inputs the same time as the regular hardware AMUX couldn't. It merely looks like a wrapper hiding the AMUX, ADC and indexing logic in a single black box, but without any added analog capabilities.  ResourceMeter indicates that it also steals 2(?!) DMA channels and huge amount of UDB resources. I use PSoC Creator  4.0 Update 1 (4.0.0.432).

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