Does the FX3 with sdk 1.3.3 support multi-bursts in the super speed mode?

[Anonymous]

        We are using the FX3 in the isochronous mode to transfer UVC data. It is based on the example code 'uvc_example/cyfxuvcinmem' in the sdk (version 1.3.3). The host is the Ubuntu Linux with libusb/libuvc. PKT_SIZE 0x400 SS_MULT 3 SS_BURST 1 Interval 1 DMA_BUF_SIZE 0x400*3*SS_BURST The endpoint uses 0x83 It works if the frame rate is low and SS_BURST=1. It fails if set SS_BURST > 1 or with high frame rates. Does the FX3 with sdk 1.3.3 support multi-bursts in the super speed mode? I see a statement in file cyfxuvcinmem.h. Does it mean SS_BURST >1 not supported? /* Burst setting for USB 3.0. UVC-Iso does not support burst as yet. */ #define CY_FX_EP_ISO_VIDEO_SS_BURST (1) and read the document AN86947 (Optimizing USB3.0 Throughput with FX3). It seems work with multi-bursts. Any advice and suggestions will be greatly appreciated   

[Anonymous]

The standard UVC driver allows the bulk implementation to set a burst length of 16.

   

But in case of Isoc: It allows MULT setting of 3, but limits BURST to 1 for USB 3.0.

[Anonymous]

Thank you for the reply.

   

Is the restriction in the host driver only? or the Cypress firmware/hardware also implemented the restriction.

[Anonymous]

The limitation comes from the UVC drivers. We have examples where FX3 stream with MULT upto 3 and burst upto 16 using Cypress drivers. Please check USBIsoSourceSink in the FX3 SDK