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cy8ckit-043 4m series -- more than 8 analog pins | Cypress Semiconductor

cy8ckit-043 4m series -- more than 8 analog pins

Summary: 5 Replies, Latest post by Bob Marlowe on 03 Nov 2016 03:50 AM PDT
Verified Answers: 1
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glenn-edgar_1523231's picture
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22 posts

I am using the CY8CKIT-043.

 

The PSOC 4m device appears to have only one a/d type which is a sequencing a/d type.

I am having trouble adding more than 8 analog pins to the a/d mux.  Problem is that after the 8 pin on the sequencing pin I yellow marker on the pin when I try the allocate more pins.  The warning legend is reachable but will lead to routing conjestion or failure.

When two or more analog muxes are used, then the pins are allocatable, but I have not found a way to connect them to the sequencing a/d.

 

What I am looking for is (2) consequentive 8 analog pins where, each pin does not have external capacitors attached to the pins.  Also I need 3 additional analog input pins.  This leads to 19 analog inputs into the A/D.

 

Is this possible?  A fallback position would be to have 19 analog input pins which do not have external capacitors connected  to them.

 

Thanks.

 

user_1377889's picture
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9608 posts

I was in contact with Cypress on a similar case, trying to route 13 analog inputs to the sequencing ADC. This is what Cypress answered;

I have got confirmation. PSoC 4200M supports 8 dedicated pins from SAR Mux, 2 pins through the analog mux bus, and 4 from opamp pins. The datasheet does not clearly mentions this. I am sorry for inconvenience. In the project, only 10 pin cannot )**EDIT** must read "can") be connected if no opamps are used. If opamps are used, it is possible to connect 4 more pins through the SAR Mux Bus.

 

Bob

glenn-edgar_1523231's picture
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22 posts

Thanks for the input Bob.

I did the following.  I made the SAR Mux A/D have one channel.  Then I placed a 19 channel analog mux in front of the SAR Mux.  I was able to build with no errors or warnings.  Have not  put code around it to test.

 

Should this work?  If so is there a more optimium way to do this, like adding more SAR Mux channels.  

Thanks

Glenn

user_1377889's picture
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9608 posts

Give it a try, I haven't tested that.

 

Bob

glenn-edgar_1523231's picture
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22 posts

Setting the PSOC 4m to one channel and feeding this input with a 20 channel analog mux allows me to read 20 pins.  The pins that are not on the p2 port have yellow channel indicators.  The project builds and successfully works in operation.

A followup question.  The technical reference manuals suggest that a sar of 16 pins can be used.  There is no example of how to do this.  Basically it appears that only 8 channels can be used by in the SAR mux.  Something is strange in that cypress designed the part for 16 channels.  Can 16 channels be used for the SAR mux?  My experience says no.

 

user_1377889's picture
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9608 posts

When some of the channels (4) come from the OpAmps you're up to 12, the remaining 4 channels are allowed for some other internal connections (I've forgotten which). Cypress promised to update the datasheet to point that out.

 

Bob

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