6 Replies Latest reply on Aug 20, 2015 2:45 AM by pavankumar.vibhute

    VRef connection to AMUX

    user_199038981

      Hi,

         

      In the datasheet of the Vref component, it specifically states that you can connect it to an AMUX and shows examples.

         

      When I connect the Vref  0.256V to the AMUX channel I get warning that there is no actual connection to the ADC_DelSig that the AMUX is connected to. What does this mean? I can read it.

         

      Nick

        • 1. Re: VRef connection to AMUX
          user_1377889

          Can you post your actual project, so that we all can have a look at all of your settings? To do so, use
          Creator->File->Create Workspace Bundle (minimal)
          and attach the resulting file.

             

           

             

          Bob

          • 2. Re: VRef connection to AMUX
            user_199038981

            Yes, here it is. A schematic pops up with ADC_DelSig on the page tab in Creator. I'm sure I'm doing something fundamentally wrong.

               

             

               

            Nick

            • 3. Re: VRef connection to AMUX
              user_14586677

              Consider filing a CASE on this, and posting back to forum what the resolution

                 

              is.

                 

               

                 

              To create a technical or issue case at Cypress -

                 

               

                 

              www.cypress.com

                 

              “Support”

                 

              “Technical Support”

                 

              “Create a Case”

                 

               

                 

              You have to be registered on Cypress web site first.

                 

               

                 

              Regards, Dana.

              • 4. Re: VRef connection to AMUX
                user_199038981

                Does anyone know right off how much time between conversion complete and output register ready to read on the ADC_DelSig.

                   

                I'm doing everything per the datasheet using ADC_DelSig_IsConversionEnd(ADC_RETURN_STATUS), however I have had to hack in delays between when the function returns non-zero and actually reading the output register result. If I wait and extra 10uS, the result is invalid, but if I wait an extra 20uS, the result is valid. This is in addition to a one pass through the program's main loop between end of conversion true and reading the output register.

                • 5. Re: VRef connection to AMUX
                  user_14586677

                  Something is wacky. 20 uS is a lot of compute time, instructions run.

                     

                   

                     

                  What does your code look like ? Sounds like your test for EOC not being tested

                     

                  right .....?

                     

                   

                     

                  Is test done in an ISR ? If so is it passing a flag out of ISR or

                     

                  variable ? If so variable should be declared as volatile.

                     

                   

                     

                  Maybe post the project -

                     

                   

                     

                  “File”                                                             Creator

                     

                  “Create Workspace Bundle”

                     

                   

                     

                   

                     

                  Regards, Dana.

                  • 6. Re: VRef connection to AMUX
                    pavankumar.vibhute

                    Hi Nick, you should be able to read output register as soons as "end of conversion (EOC)" triggers. Can you provide your project ?