2 Replies Latest reply on Jul 1, 2019 5:51 AM by dacuc_1521966

    writing serial number into CY7C65211


      The CY7C65211 USB-Serial chip has a place to hold a serial number.  However, though Cypress's USB-Serial Configuration Utiility shows the current serial number (if any), it doesn't seem to allow writing a new serial number.  It looks like it would be obvious and easy but it isn't working for me to enter a string of characters for programming through the Configuration Utility.  How does one write a new string into the Serial Number location of a CY7C65211?

        • 1. Re: writing serial number into CY7C65211



          In the USB tab of Configuration Utility, check the box which says "Use serial number string" and then you can enter the required serial number to that specific part.

          Please have a look at the attached snippet of configuration utility.


          The CY_DEVICE_INFO structure and CyGetDeviceInfo or CyGetDeviceInfoVidPid  API can be used to retrieve the serial number of a part in an application by passing the device number or vidPid of the device of interest. Please refer to USB-Serial API Guide section 3.4, 4.4 and 4.5.




          Best Regards,


          • 2. Re: writing serial number into CY7C65211

            We tried again, as you suggested, but this time we cycled the power after writing the serial number and before checking to see if the serial number was there.  The serial number was programmed as we wanted.  Certainly, our experience with using Cypress's USB-Serial Config Utility to configure a new chip from its factory default to I2C operation is that the PID does not change as shown in Config Utility until after the power is cycled (a lesson learned the hard way).  Based on this recent experience with the serial number, it appears that the power must be cycled before the config utility shows the newly programmed serial number.  Whatever the details are, it's working for us now.  Thank you for confirming the process.  I will mark this question as "Answered".