5 Replies Latest reply on Nov 30, 2018 2:03 AM by Dávid Ágoston

    Programming a CY8C26643-24AI with miniProg3



      I have a problem with the following case and I'm looking for help:


      We tried to program the CY8C26643-24AI chip with miniProg3, using ISSP protocol.

      The programming configuration in the PSoC programmer were as follows:

      Programming mode - Reset;

      Verification - Yes;

      Auto Detection - Yes;

      Protocol - ISSP;

      Voltage - 5.0V


      Ultimately, we cannot program the device, the device cannot be indentified (nonetheless, we even tried to fiddle with the aforementioned parameters as well- which we think is the right one -  in hope for a better outcome. Failed. Naturally.). On the SDAT pin, we experience (by using an oscilloscope) that the PSoC1 sends a signal alternating between 4V and 5V, but only when responding to the programmer. (there are no other parts of the circuit that may cause this) This signal is read as 0xFFFF. Do you have any suggestions what can be the problem?


      I've previously read that maybe if the device is configured for I2C comunication, it can sabotage the reprogramming. If this is the case (I've no idea) then what are the proper countermeasures to solve this?


      Thanks in advance,



        • 1. Re: Programming a CY8C26643-24AI with miniProg3

          Hi Dávid,


          Is this device fresh chip or programmed before?

          Has it being programmed successfully before?

          Are there any capacitors on programming line traces(SDA, CLK, XRES)? Please have a try with other devices or MiniProg-3, and make sure programming cable is not too long.




          • 2. Re: Programming a CY8C26643-24AI with miniProg3

            Hey Ryan,


            Thanks for answering.


            The chip was bought from ebay, and was probably programed by the vendor (altough claimed to be a fresh chip). We could never program it successfully.
            Our miniProg3 is working perfectly fine, we are flashing PSoC 4 and 5 devices on almost a daily basis.

            We have our own design for the PCB the chip is used in, and there are no capacitors on any of the programming traces, neither is the programming line too long (apart from the standard miniProg cable, the trace on the PCB is max. 1 or 2 cm-s long).


            I am attaching a screenshot from our oscilloscope which depicts the last transmission before the PSoC programmer fails the programming (with error mesage: Programming failed, device ID FF FF FF FF is not found in library - or something along those lines)

            On the oscilloscope screen, the yellow line is the SDAT and the blue line is the SCLK traces.




            We suspect that the signal levels of the response on the SDAT are incorrect (even though the SDAT is pulled to the GND via a 330ohm resistor)


            All the Best,



            • 3. Re: Programming a CY8C26643-24AI with miniProg3

              I have never seen (yet) SDAT (or SCL) pulled low and 330 ohm is very small value. Did you set programmer protocol to ISSP?




              • 4. Re: Programming a CY8C26643-24AI with miniProg3

                Dear Bob,


                The programmer protocol was ISSP, as stated in the original post, where most of the circumstances are elaborated in details.


                all the Best,



                • 5. Re: Programming a CY8C26643-24AI with miniProg3

                  The chip at hand is not supported anymore and there were a number of devices which were sold, but still at the prototype phase. All bugs were resolved in a later chipset that was released very soon after this one.

                  This particular chip probably has hardware default or locked memory area (as deducted from my conversation with an expert on this product line)