7 Replies Latest reply on Sep 5, 2018 5:22 AM by SrinathS_16

    fx2lp cdc class control

    gean_3054931

      Hello,

      we are implemented CDC class in fx2lp.fx2lp is interfaced with image sensor in slavefifo configuration.we are developing

      an android application.we are trying to recieve the image data from the fx2lp through usb (cdc class implemented).

      because of contineous data from the usb,our android application.is not able to recieve the correct image data.so we need control

      in the fx2lp side.is there any control (software/hardware) to control the flow of data from the fx2lp.

      like cts,rts signals?

      how to control data flow in the android application?

      any control signals are there for the above scenario?

      if it is cdc class,is there any tokens/siganls of USB that can acts as a cts or rts(like in uart) flow control signals?

      if anything is there reagarding this,let me know.

       

       

      regards,

      geetha.

        • 1. Re: fx2lp cdc class control
          SananyaM_56

          Hi Geetha,

           

          For the FX2LP, you can send a command  over I2C interface to your image sensor but the command should be supported by the sensor. From your host application, you can implement flow control by setting RTS signal which should send appropriate SetControlLineState request to the FX2LP based on which the data received from the image sensor can be committed to the host in the firmware.

           

          Best Regards,

          Sananya

          • 2. Re: fx2lp cdc class control
            gean_3054931

            Hello sananya,

            For the FX2LP, you can send a command  over I2C interface to your image sensor but the command should be supported by the sensor.

            -->what do you mean by command should be supported by the sensor?what type of command?

             

            you can implement flow control by setting RTS signal.

            ->but fx2lp 56 pin doesnot have uart signals physically,how can i implement this RTS signal in CDC class?please tell me clearly.

             

            regards,

            geetha.

             

            • 3. Re: fx2lp cdc class control
              SrinathS_16

              Hello Geetha,

               

              FX2LP 56-pin has not got physical UART and so it does not make much difference whether you implement it in CDC class or vendor class. Also, CDC class is generally meant for COM port devices and not for camera applications. In case you want to implement CDC class for video devices, you cannot perform the UART flow control since there is no hardware UART block on the IC.

               

              Best regards,

              Srinath S

              • 4. Re: fx2lp cdc class control
                gean_3054931

                Hello shrinath,

                thanks for your reply.

                you cannot perform the UART flow control since there is no hardware UART block on the IC.

                ->if there is no hardware control,is it possible to do software control?

                usb can act as uart(virtual com port) when CDC class implemented.

                can we control data flow from fx2lp to pc using xon/xoff protocols?is it applies to this sitauation?

                can we control data flow with USB signals/tokens/registers?

                 

                regards,

                geetha.

                • 5. Re: fx2lp cdc class control
                  SrinathS_16

                  Hello Geetha,

                   

                  - In case you have interfaced the FX2LP to an FPGA and then an image sensor, you can use the FX2LP flags or a GPIO pin to indicate the FPGA to stop/start sending the data.

                  - In case you have connected the FX2LP directly to the image sensor, then the image sensor continuously sends data to the FX2LP and there is no control that can be implemented.

                   

                  Best regards,

                  Srinath S

                  1 of 1 people found this helpful
                  • 6. Re: fx2lp cdc class control
                    gean_3054931

                    Hello shrinath,

                    Flow control in USBUART

                    I have found above thread in the community,is it applies to cdc class ?

                    can i refer USBUART for CDC class?

                    if USBUART and CDC class are different,please let me know?

                     

                    regards,

                    geetha.

                    • 7. Re: fx2lp cdc class control
                      SrinathS_16

                      Hello Geetha,

                       

                      CDC is a USB defined class that is generally used for virtual COM port devices (UART or RS232 interfaces) but it does not mean that they are the same. CDC class implementation would make sense only when the device that is used has got a UART or RS232 interface but USB does not restrict from using CDC class for other interfaces. In such cases where CDC class is used for different interfaces, the flow control cannot be implemented as in UART.

                       

                      Best regards,

                      Srinath S

                      1 of 1 people found this helpful