3 Replies Latest reply on Oct 14, 2019 10:59 PM by RakshithM_16

    Current sinking capability of XRES in MiniProg3.

    JoBe_296651

      Howdy.

      We have a design for the 48-pin PSoC 3 that requires GPIO functionality of the XRES pin with a strong pullup (~10mA) on the PCB. Can the MiniProg3 be used for initial reset-mode programming with this pullup in place?  Also, is the schematic for MiniProg3 available for download? I couldn't find a link.

      Thanks in advance.

        • 1. Re: Current sinking capability of XRES in MiniProg3.
          RakshithM_16

          Hi JoBe_296651,

           

          MiniProg3 design and schematic is proprietary of Cypress and cannot be shared.

           

          According to my understanding you have connected an external pull-up resistor at P1.2 which is needed for your project and you are using P1.2 as a GPIO pin. Please correct me if I am wrong.

           

          48 pin PSoC 3 devices do not have a dedicated XRES pin. P1.2 can be used as XRES or GPIO pin (default = XRES pin).

          If P1.2 is used as XRES pin then it can no longer be used as a GPIO pin. Only way to do this is to reprogram the device after setting P1.2 as GPIO pin. Similarly, if P1.2 is set as GPIO pin you cannot use it as XRES pin and needs to be reprogrammed.

           

          Note that if P1.2 is set as GPIO then Power cycle mode programming is the only available option.

           

          For further details regarding programming modes and P1.2 pin configuration of 48 pin PSoC 3 devices please refer the PSoC 3 Device Programming Specifications document - https://www.cypress.com/file/44676/download

           

          Thanks and Regards,

          Rakshith M B

          • 2. Re: Current sinking capability of XRES in MiniProg3.
            JoBe_296651

            Hello Rakshith. Thank you for your time.

             

            We would like to have our boards fully assembled before programming, and as you noted the NVL default for P1.2 is XRES.  Therefore initial programming of the device can be done in reset mode, but the external pullup resistor needed for GPIO would already be in-circuit. Our concern is that the additional 10mA from this pullup might be a problem for the MiniProg3. Debug and reprogramming of the PSoC won't be necessary.

             

            Thanks again.

            Jon

            • 3. Re: Current sinking capability of XRES in MiniProg3.
              RakshithM_16

              Hi JoBe_296651,

               

              If the supply used is 3.3 V then it will not be an issue. The MiniProg 3 can sink up to 8 mA current when 1.8 V supply is used and it can sink up to 12 mA current when a supply greater than 2.5 V is used. It is advised not to use 5 V supply as it can create issues. I tried programming with 3.3 V supply and giving a 12 mA total pull up on P1.2 and I was able to program the device successfully.

               

              Thus, a MiniProg 3 device can be used to initially program your device using reset mode programming.

               

              Also note that, the MiniProg3 programmer is not recommended for production programming. We suggest customers who need production programming support to consult our 3rd party programming vendors on our General Programming page or through our distribution partners: https://www.cypress.com/go/distributors

               

              Thanks and Regards,

              Rakshith M B