1 Reply Latest reply on Sep 18, 2020 9:24 PM by EktaN_26

    USB "Not Recognized" on some lot numbers, but fixed by updating cy_boot 5.60→5.70?


      We've been making a product with CY8C4246AZI-L433 for a while, but now there is an issue where ICs from a certain lot number aren't working over USB.  The firmware seems to be working otherwise, but the USBFS component never transmits anything.


      I got one such unit from the factory and found that the USBFS Bootloader project, installed by itself, still shows the Not Recognized problem with the original cy_boot 5.60, but after updating to cy_boot 5.70, it works correctly.  Any idea what might be causing this?


      The cy_boot datasheet says that 5.70 has "Updated algorithm of the USB lock/unlock functionality. Enhancement for PSoC 4200L device".  I'm not sure what this means, but it might be related?


      When debugging the bad IC and pausing it after enumeration has failed, it seems to just be waiting inside USBFS_CyBtldrCommRead, either at

      /* Wait unitl host writes data into OUT endpoint. */

      or at

      /* Wait for enumeration first time. */ ... /* Wait for device enumeration. */


      But the Host has already sent setup transactions with no ACK from the PSoC: