Details of Configuration Registers

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Anonymous
Not applicable

I am developping one psoc based product. In which I have to use ins amp.

   

Many times i used to make offset voltage zero.

   

For doing this I have to connect inverting and non inverting terminals to each other (SHORT)

   

I want to do this in runtime

   

Again I want to disconnect them.

   

 

   

How to do do this is run time. Please explain 

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ETRO_SSN583
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Depending on where the IA is placed you would use register writes

   

to the analog column INV input control register. Take a look at

   

ACBxxCR1 in the TRM (Technical Reference Manual). This register

   

controls a mux, as well as other stuff, the selects where INV input

   

gets its signal.

   

 

   

Generally when you change a blocks settings you issue a STOP() to

   

the block, its clocks (if applicable), do the changes, and restart the block.

   

 

   

Regards, Dana.

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ETRO_SSN583
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One other thought, when you tie the inputs together make sure

   

they are terminated in some driven voltage, eg. not floating, otherwise

   

you would get readings from A/D measuring offset drifting due to finite

   

CMR of IA.

   

 

   

This ap note may also be of interest, correlated double sampling for

   

noise rejection. http://www.cypress.com/?rID=2894    AN2226

   

 

   

Regards, Dana.

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Anonymous
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        To use AMux is easy way to do this   
Like this...   
BTW, Don't do Multi Post   
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ETRO_SSN583
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Don't confuse AMUXn, which is a mux module you place/add to a design,

   

and the AnalogColumn_InputMUXn shown in prior post, INSAMP1.jpg.

   

That mux is always present, part of the HW routing resources.

   

 

   

The AnalogColumn_InputMUXn is controled by the register write I referred

   

to in my earlier post.

   

 

   

Regards, Dana.

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Anonymous
Not applicable
        What you talkin about?   
Amux can control by API (its easy than by resister)   
Don't you know??   
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ETRO_SSN583
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What you showed in INSAMP1.JPG was a route, done by register, to

   

tie the INV input to the NINV input. That is a single register write, a one

   

line command, that writes a byte with specific bit settings, that controls

   

AnalogColumn_InputMUXn to accomplish that route.

   

 

   

If you used AMUXn, yes, a one line command, API, could also be used.

   

But that requires additional HW and its attendant API code.

   

 

   

So why do you think thats "easier" ? I think its pretty much same, and you

   

save FLASH, 25 bytes, and allow HW (AMUXn) to be used for something

   

else.

   

 

   

Regards, Dana.

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ETRO_SSN583
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Almost forgot, using AMUXn requires at least 2 lines of code,

   

a Start() command and a Select() command.

   

 

   

Regards, Dana.

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