6 Replies Latest reply on Dec 2, 2012 11:58 PM by rama.sai.krishna.vakkantula

    What bandwidth in bulkloop example?

    lee.carter

       Hi

         

      I have 3 question about fx3. 

         

      If i use bulkloop example for HD 720p, is bandwidth or speed enough ?

         

      Why bulkloop example have not GPIFdesigner project file?

         

      What case need GPIF desiner?

        • 1. Re: What bandwidth in bulkloop example?
          content.librarian

          Hi

             

          >> If i use bulkloop example for HD 720p, is bandwidth or speed enough ?

             

          I am not sure how you like to use it, but I think the bandwidth depend on DMA buffer size and count.

             

          >> Why bulkloop example have not GPIFdesigner project file?

             

          because bulk loop just receive data from U-port (an USB OUT endpoint) and forward the data directly to U-port (an USB IN endpoint). It is a loop!!!

             

          >> What case need GPIF desiner?

             

          If you are using the GPIF interface. The data and control lines of the interface e. g. see UVC example or slave fifo examples.

             

          regards,

             

          lumpi

          • 2. Re: What bandwidth in bulkloop example?
            lee.carter

             Thanks advice,

               

            You said like following

               

             >> Why bulkloop example have not GPIFdesigner project file?

               

             

               

            because bulk loop just receive data from U-port (an USB OUT endpoint) and forward the data directly to U-port (an USB IN endpoint). It is a loop!!!

               

             

               

            What if i use bulkloop(but make not loop) for video data receving,

               

            I thnk that it can make more effectivly data transfertation that UVC.

               

            Because UVC have redandancy overhead, so i think that this is more effectable way for bulkloop in endpoint with video port and out endpoint with host. 

               

             

               

            What is your opinion?

               

             

               
                    
            • 3. Re: What bandwidth in bulkloop example?
              content.librarian

              Hi,

                 

              sorry but I can not follow your description.

                 

              Bulkloop is a loop in DMA auto or manual mode. So the producer socket of the dma is connected to an OUT endpoint and the consumer socket is connected to an IN endpoint. So all what you send from host via the OUT endpoint will be mirrored back to the IN endpoint. In case of fx3 dma manual mode you have to commit in dma callback and in case of auto it works automatically in your application on fx3.

                 

              So how you connect the video port? What is your meaning of a video port?

                 

              Is it right, that it is any hardware which you like to connect to the GPIF interface?

                 

              thanks,

                 

              lumpi

              • 4. Re: What bandwidth in bulkloop example?
                lee.carter

                 Bulkloop is a loop in DMA auto or manual mode. So the producer socket of the dma is connected to an OUT endpoint and the consumer socket is connected to an IN endpoint. So all what you send from host via the OUT endpoint will be mirrored back to the IN endpoint. In case of fx3 dma manual mode you have to commit in dma callback and in case of auto it works automatically in your application on fx3.

                   

                So how you connect the video port? What is your meaning of a video port?

                   

                Is it right, that it is any hardware which you like to connect to the GPIF interface?

                   

                thanks,

                   

                lumpi

                   

                 

                   

                ---------------------------------------------------------------------------------------------------------------------------------

                   

                Thanks,  may be i have not totally understading bulkloop.

                   

                I mean that The Video ports are Hsync, Vsync, Data[7:0] of camera.

                   

                 

                   

                I think like that camera's output port pins (Hsync, Vsync, Data[7:0]) connect to FX3 GPIO pins.

                   

                Then, i read camera's output port pins (Hsync, Vsync, Data[7:0]) from FX3 GPIO pins by bulkloop mode.

                   

                 

                   

                But as your word, bulkloop is just switching receive data from U-port (an USB OUT endpoint) and forward the data directly to U-port (an USB IN endpoint). 

                   

                 

                   

                So, if i use video camera interface with fx3, i need GPIF DMA scheme(not bulk mode but slavefifo or etc..)

                   

                 

                   

                Is this correctly right my think?

                • 5. Re: What bandwidth in bulkloop example?
                  content.librarian

                  Yes, that's right.

                     

                  You need slave fifo but for this you need additional a FPGA. Or you use the UVC GPIF II project and you make your own application around it. or you are using your own GPIF II project based on the UVC GPIF II,...

                     

                  many possibilities but with a sensor you need the GPIF II interface.

                     

                  regards,

                     

                  lumpi

                  • 6. Re: What bandwidth in bulkloop example?
                    rama.sai.krishna.vakkantula

                    Hi Dv2,

                       

                    Please refer to the following application note:

                       

                    AN75779 - Interfacing an Image Sensor to EZ-USB® FX3™ in a USB video class (UVC) Framework

                       

                    http://www.cypress.com/?rID=62824

                       

                    I hope this application note gives you a good start for implementing your application with FX3.

                       

                    Thanks,

                       

                    sai krishna.