Hi all,
Can anyone help me with how the calcultions in Table 5-2 on page 42 of
USB2.0 spec are done.Awaiting your response
Thanks
Rajesh

On Mon, 2004-02-16 at 14:21, i_rajesh1@rediffmail.com wrote: Ahh, you finally found the bandwidth tables !!! ;*) Lets see: Max Bandwidth = (45 bytes protocol over head + Bytes/frame useful data + Bytes Remaining) * Max Transfers Basically you calculate the maximum possible data amount you cant transfer for a certain packet size (Data Payload). The protocol overhead is fixed, depending on the Payload Size, you can transfer a certain number of packets in one frame (Max Transfers). The remaining bytes is the wasted bandwidth due to Frame utilization. As you can see the larger the packet the better is the utilization. However if you have to resend one of the large packets due to some transfer errors, your utilization drops dramatically. So you need to find the best solution for your application. Fo video applications, I would suspect isochronous endpoints would be more appropriate, and you should look at the tables on pages 45 and 46. Regards, rudi ======================================================== ASICS.ws ::: Solutions for your ASIC/FPGA needs ::: ..............::: FPGAs * Full Custom ICs * IP Cores ::: FREE IP Cores -> http://www.asics.ws/