1 Reply Latest reply on Jan 24, 2017 12:32 AM by keaj

    CX3 USB UART Example: Not working

    priyanob_2031756

      Hi,

         

      I tried running USB-UART example for both FX3 and CX3. For both the boards, the device got registered. But, the data transmission happened only with FX3 and not with CX3. Below is what I did for testing.

         

      FX3:

         

      1) Device got registered as COM device with port 22

         

      2) The Debug port of FX3 got registered with port 23

         

      3) Opened both the above serial ports with two applications (Terra Term) and the data I entered in one terminal got received on the other terminal.

         

      4) Thus, example works for FX3

         

       

         

      CX3:

         

      1) Device got registered as COM device with port 22

         

      2) Connected the serial cable to the UART port (COM1).

         

      3) Opened both the above serial ports with two applications (Terra Term) and no data appeared when I did same thing as with FX3.

         

       

         

      Can you please help me out what has to be done for CX3 also to work like FX3? Will it work with Linux too?

        • 1. Re: CX3 USB UART Example: Not working
          keaj

          Hi,

             

           

             

          In FX3  chip, SPI, UART, and I2S interfaces are multiplexed on the serial peripheral port.UART lines can be routed either on GPIO[46]-GPIO[49] or on GPIO[53]- GPIO[56] pins of FX3. When you are selecting the LPP mode as UART_ONLY the UART pins will be routed to GPIO[53]- GPIO[56] as per Table 7 of FX3 datasheet. 

             

          In case of CX3, the routing of UART pins are fixed, not multiplexed. In this case you have to change the LPP mode to CY_U3P_IO_MATRIX_LPP_DEFAULT instead of CY_U3P_IO_MATRIX_LPP_UART_ONLY. After making this change you can rebuild the firmware. The USB UART example will work with CX3.

             

           

             

          Thanks and Regards,

             

          Keerthy