We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi,
I am working on LPC1768 and using example USB CDC. It is working on Bulk transfer. I want to convert that example to Isochronous transfer but when i changed the Endpoint number its not transfer or receive any data with host. what will be the reason as there is no error in code. Please Help me in solving this problem. Thanks advance
Bulk is great for sending files over USB - grab all free bandwidth.
Isochronous is great when you need guaranteed bandwidth for some real-time stream.
If listening to music, it makes a difference if a damaged frame gives a short drop-out, or if the music freezes and the music then comes back with a time delay from the resend. That time-delay would mean everyone dancing to the music suddenly ended up being out of sync with the music.
There are several transfer modes for the simple reason that there are different needs to optimize for. So don't ignore Bulk, if it's actually Bulk that best matches your needs.
@Hans-Bernhard Broeker you are right. As i am new in USB development thats why i was confused. So please don't mind it.
@Per Westermark Thanks for the great help.
if you don't mind one thing i want to ask both of you. As bulk Endpoints support 64 bytes. That 64 bytes in per millisecond or per second and what will be the maximum of baudrate that it can support? Thanks in advance.
As stated before there can be multiple of 64 bytes per ms, for example mass storage device (USB Flash disk) using bulk transfers can get around 1MB/s transfer on full speed bus, so that is the maximum that you can expect on CDC also.