2 Replies Latest reply on Jan 16, 2013 2:02 AM by userc_39074

    Problems with 26MHz Clock and maybe old stepping

      First of all I wanted to wish everyone here a happy new year!


      However new year -> new problems!


      I have got my board with the FX3 now and have detected a problem with the clock or the UART baudrate.     



      I am using a 26MHz clock and not a 19,2 MHz crystal. The FSLC-Pins are "101" as described in the datasheet. I can load software to the FX3 via USB and via J-Link Debugger.


      However the UART does not work, because the baudrate is not correct. It should be 115200 Baud but it is 156000 Baud (measured with a scope). This is 115200 * (26/19.2). This looks like the baudrate is calculated on a 19.2MHz base.


      To find a solution, I have modified the startup code a little bit to:




      CyU3PSysClockConfig_t clkCfg;


      uint32_t sysclk;


      CyU3PPartNumber_t partnumber;



      /* Initialize the device */




      clkCfg.setSysClk400 = CyTrue;


      clkCfg.cpuClkDiv = 2;


      clkCfg.dmaClkDiv = 2;


      clkCfg.mmioClkDiv = 2;


      clkCfg.useStandbyClk = CyTrue;


      clkCfg.clkSrc = CY_U3P_SYS_CLK;


      status = CyU3PDeviceInit (&clkCfg);
      if (status != CY_U3P_SUCCESS)


          goto handle_fatal_error;



      status = CyU3PDeviceGetSysClkFreq (&sysclk);


      if (status != CY_U3P_SUCCESS)




          goto handle_fatal_error;




      partnumber = CyU3PDeviceGetPartNumber();     





      However this makes no difference to CyU3PDeviceInit (NULL).


      The CyU3PDeviceGetSysClkFreq returns a SysClock of 403.2 MHz. This should be 416 MHz with a 26 MHz clock. Looks like the configuration pins are not detected correctly, but I have checked them several times.     



      At least the partnumber is returned correctly as CYPART_USB3014.     



      I have also a problem with the default VID/PID of the part. This is not 04B4/00F3 but 1480/0000. I have found an article that this is the case with an old revision of the chip. As mentioned, I have modified the Inf-File for this VID/PID. Though my board is pretty new, the chips seem to be pretty old. They are labeled:




      I      1149


      A    33 PHI




      Do I have to expect other problems with this revision? When I am ordering new chips, how can I find out, that I get actual parts?