4 Replies Latest reply on Feb 16, 2017 5:37 AM by edgargomez.ucv_2267546

    How to know this values packets per burst and bursts per microframe.

    edgargomez.ucv_2267546

      I am using the FIFO port with 8bit 1024 Bytes Quad buffer isochronus, how to know  packets per burst and bursts per microframe. I am trying to read from the host. My usb is the CY7C68013A

         

       

         

      Thanks

        • 1. Re: How to know this values packets per burst and bursts per microframe.
          nisa

          This field is set in the USB device descriptor. Later you can query the device descriptor to know the bursts and the number of packets per burst 

          • 2. Re: How to know this values packets per burst and bursts per microframe.
            edgargomez.ucv_2267546

            Thanks for response.

               

            Even if use the FIFO sending automatically the data when the buffer fills, the packets per burst and bursts per microframe are set in the setupdata?

               

             

               
                

            Bus 002 Device 004: ID 04b4:1004 Cypress Semiconductor Corp.
            Device Descriptor:
              bLength                18
              bDescriptorType         1
              bcdUSB               2.00
              bDeviceClass            0 (Defined at Interface level)
              bDeviceSubClass         0
              bDeviceProtocol         0
              bMaxPacketSize0        64
              idVendor           0x04b4 Cypress Semiconductor Corp.
              idProduct          0x1004
              bcdDevice            0.00
              iManufacturer           1 Cypress
              iProduct                2 DMB-TV
              iSerial                 0
              bNumConfigurations      1
              Configuration Descriptor:
                bLength                 9
                bDescriptorType         2
                wTotalLength           25
                bNumInterfaces          1
                bConfigurationValue     1
                iConfiguration          0
                bmAttributes         0x80
                  (Bus Powered)
                MaxPower              100mA
                Interface Descriptor:
                  bLength                 9
                  bDescriptorType         4
                  bInterfaceNumber        0
                  bAlternateSetting       0
                  bNumEndpoints           1
                  bInterfaceClass       255 Vendor Specific Class
                  bInterfaceSubClass      0
                  bInterfaceProtocol      0
                  iInterface              0
                  Endpoint Descriptor:
                    bLength                 7
                    bDescriptorType         5
                    bEndpointAddress     0x82  EP 2 IN
                    bmAttributes            3
                      Transfer Type            Interrupt
                      Synch Type               None
                      Usage Type               Data
                    wMaxPacketSize     0x0400  1x 1024 bytes
                    bInterval               1
            Device Qualifier (for other device speed):
              bLength                10
              bDescriptorType         6
              bcdUSB               2.00
              bDeviceClass            0 (Defined at Interface level)
              bDeviceSubClass         0
              bDeviceProtocol         0
              bMaxPacketSize0        64
              bNumConfigurations      1
            Device Status:     0x0000
              (Bus Powered)

                

             

               
            • 3. Re: How to know this values packets per burst and bursts per microframe.
              nisa

              I see that you have updated the post with your part number:CY7C68013A: This is a high speed part. High-speed does not allow burst mode. You can only have mult setting: number of packets per burst (burst is always 1 in high speed). In the endpoint descriptor you can set this by setting the max packet size accordingly. In the above descriptor I see max packet size of 1024, which you can change upto 3072 which effectively will reflect the 3 packets per burst. 

              • 4. Re: How to know this values packets per burst and bursts per microframe.
                edgargomez.ucv_2267546

                Thanks for the support, i see the endpoints descriptors.

                   

                Solve it