7 Replies Latest reply on Sep 1, 2014 6:24 AM by user_669821

    RefMux with CY8C28623

    user_669821

      Hi everybody,

         

      I'd like to use the RefMux module on a CY8C28623 to route signals to the analog output bus.

         

      When I place the RefMux (v1.3 in PSoC Designer 5.4) I don't see any link appearing between the AnalogColumn_InputSelect multiplexer and the RefMux itself, as it happened using other PSoCs like CY8C27443 for example.

         

      Furthermore the RefMux v1.3 datasheet doesn't report the CY8C28623 in the list of compatible devices: CY8C29/27/24/22xxx, CY8C23x33, CY8CLED02/04/08/16, CY8CLED0xD, CY8CLED0xG, CY8CTST120, CY8CTMG120, CY8CTMA120, CY8CTST300, CY8CTMA300, CY8C28x45, CY8CPLC20, CY8CLED16P01, CY8C28x43.

         

      So I would like to know if I can use this module and which is the correct way to do it with CY8C28623.

         

      Many thanks in advance.

         

      Marco

        • 1. Re: RefMux with CY8C28623
          user_1377889

          Are you mistaking RefMux and AMUX ?

             

          Bob

          • 2. Re: RefMux with CY8C28623
            user_14586677

            Looks like the P/N not in datasheet a simple omission. If RefMux placed code

               

            is generated for its API's and definitions, eg, looks like it is a normal accessable

               

            component/module for the 28xxx series of parts.

               

             

               

            I concur with Bob, RefMux does not "feed" the column mux, you are thinking of

               

            AMUX.

               

             

               

            Regards, Dana.

            • 3. Re: RefMux with CY8C28623
              user_669821

              Dear Bob and Dana,

                 

              thank you for your replies, I'm referring to RefMux.

                 

              As reported in the datasheet the RefMux can be used to provide "... a method to route external analog inputs directly to the analog output bus" (from the datasheet), by selecting the PMuxOut input.

                 

              The attachment "RefMuxPlacement.jpg" report the use of RefMux in a CY8C27443 project where you can see the link between the analog mux output and the RefMux input; if I use the CY8C28623 this link can't be established, maybe it is only a "graphical" issue.

                 

               

                 

              Please let me know your opinion.

                 

               

                 

              Regards,

                 

              Marco

              • 4. Re: RefMux with CY8C28623
                user_1377889

                There is no connection between an input pin of port0 to the RefMux output and analog buf. You only may select from the sources from the list. The connection is as unusable as the clock source selection for a column connected to a ctb (upper row). When you want to route different pins to the output buffer, use a PGA gain 1.0 and make the appropiate connections.

                   

                 

                   

                Bob

                • 5. Re: RefMux with CY8C28623
                  user_14586677

                  Yes, using the PMUXout input to the RefMux one of 4 pins can be routed

                     

                  direc tly to the analog output buffer. I also concur that one cannot

                     

                  "see" the route.

                     

                   

                     

                  The RefMux User Module switches one of three internal references (AGND, REFLO, or REFHI) to the analog output bus. Additionally, the output of the Continuous Time (CT) block PMux multiplexer can be selected. The RefMux User Module makes use of the TestMux in a CT block. These signals may be routed to a switch capacitor block on the bottom analog row or buffered and routed to an external pin. If used in conjunction with the AMux4 User Module, they form a four input analog multiplexer to route signals from one of four pins to the analog output bus.

                     

                   

                     

                  Figure 1. RefMux Block Diagram

                     

                   

                     

                  • 6. Re: RefMux with CY8C28623
                    user_14586677
                          
                    • Low voltage offset path from PMux to analog output bus
                    •     
                    • Provides a method to route internal references (AGND, REFHI, REFLO) to an external pin
                    •     
                    • Provides a 4 to 1 analog mux for switch capacitor blocks such as ADCs and filters, if used with the AMux4 User Module
                    •     
                    • Signals from PMux through test mux may be rail-to-rail
                    •     
                    • Provides a method to route external analog inputs directly to the analog output bus
                    •    
                       

                     

                       

                    Be carefull regarding the statement about R-R performance. That is true until you pass

                       

                    thru the output buffer, then a combination of its CM input range and output CM range

                       

                    destroy all R-R performance.

                       

                     

                       

                    Regards, Dana.

                    • 7. Re: RefMux with CY8C28623
                      user_669821

                      Dear Dana, thank you for your reply.

                         

                       

                         

                      Regards,

                         

                      Marco