USB3.0 ISO maximum high-bandwith test | Cypress Semiconductor
USB3.0 ISO maximum high-bandwith test
Accoding to USB3.0 specification, SuperSpeed isochronous transfer type can move up to 1024 x 16 x 3 bytes per service interval. Taking the minimum service interval as 125 µs, the maximum theoretical bandwidth for SuperSpeed isochronous transfer can be calculated as (maximum packet size * burst size * number of iso-packets / service interval). That works out to 1024 x 16 x 3 / 125µ bytes/s or 375 Mbytes/s (3 Gbps)
The throughput depends on the burst length, buffer size, iso-packets, and the number of DMA buffers used.
When ISO Burst is 16, iso-packets is 3, buffer size is 3*16*1024, and the number of DMA is 3, limited to 256KB DMA size.
dmaCfg.size = (CY_FX_ISO_PKTS * CY_FX_ISO_BURST)*size;
Then transfer performance of USB3.0 ISO can be measured best.