3 Replies Latest reply on Jun 13, 2014 5:57 PM by user_14586677

    Reducing power consumption in CY8C20xx7

    cliff.wallach

       In order to reduce power consumption as much as possible in a CY8C20xx7,  the device will repeatedly make measurements and then enter sleep mode for a while.  What  hardware can be switched off while sleeping and then quickly switched on to make measurements?  Specifically the control bits cleared in CSDPLUS_Stop.  Also how much power is reduced and are there any issues, delays or reinitializations needed for the following components cleared in the stop function:

         

      _`@INSTANCE_NAME`_Stop:

         

      .....

         

       

         

         M8C_SetBank0

         

         ; and     reg[AMUXCFG], ~0ch ; Disconnect internal capacitor

         

         and   reg[`@INSTANCE_NAME`_CapSense_CR2_REG], ~`@INSTANCE_NAME`_CS_CR2_INIT ; Disable precharge switching and disconnect IDAC

         

         and   reg[`@INSTANCE_NAME`_CapSense_CR0_REG], ~08h ; Disable CSDPLUS mode

         

         and   reg[`@INSTANCE_NAME`_CapSense_CR3_REG], ~`@INSTANCE_NAME`_CS_CR3_INIT ; Power down and disconnect VRef Buffer

         

         mov reg[`@INSTANCE_NAME`_CapSense_PRS_CR_REG], 00h  `@CTAB40`; Disable PRS

         

         RAM_EPILOGUE RAM_USE_CLASS_1

         

         ret

         
              
         
              
         
          Thanks   
         
              
        • 1. Re: Reducing power consumption in CY8C20xx7
          user_14586677

          You have had a chance to look at this -

             

           

             

              

             

                    

             

          http://www.cypress.com/?rID=34189     AN47310

             

           

             

           

             

          Regards, Dana.

          • 2. Re: Reducing power consumption in CY8C20xx7
            cliff.wallach

            That document doesn't seem to handle the CY8C20xx7.  Instead it covers  Associated Part Family: CY8C21x23, CY8C21x34, CY8C21x45, CY8C22xxx, CY8C23x33,  CY8C24x23A, CY8C24x94, CY8C27x43, CY8C28xxx, CY8C29x66

               

            In any case, what analog components can be powered down then powered up without affecting capsense?   I'd expected the analog block references would be reset, but what about the analog output buffers and CT/SC blocks?  Also, what time delay is needed between powering them up and using them?  This isn't mentioned in any of the documents I've read.

               

            Thanks

            • 3. Re: Reducing power consumption in CY8C20xx7
              user_14586677

              I included the doc link because the 20xx7 parts are of same basic technology.

                 

              I also cannot find answers that cover your questions, Even the TRM is very "thin" on this

                 

              family.

                 


                 

              I think you should file  CASE -

                 


                 

                   

                 

                          

                 

              To create a technical case at Cypress -

                 

               

                 

              www.cypress.com

                 

              “Support”

                 

              “Technical Support”

                 

              “Create a Case”

                 

               

                 

              You have to be registered on Cypress web site first.

                 

               

                 

              Regards, Dana.