thanks... i recognize the name as the author of the SL811 cypress driver????
if you are the author... may i ask whether it utilizes the A/B feature of the chip? from looking at it.. it does not seem to do so Pei Liu wrote: > > As far as performance goes, there are two things you have to consider: > > 1) The SL811HS is a bit-banger. The driver receives an USB transfer Done > interrupt on each USB transaction. In each USB Frame, there can be multiple > USB transactions. I remember that in a USB mass storage device, there can > be up to 10 USB transactions in a frame. This means that the driver can > received 10 USB Done interrupt in 1 millisecond time frame. > > 2) In addition to the USB done interrupt, the driver receives 1MS > interrupt. This 1MS interrupt can not be slow down because it is used to > indicated the start of the frame, keep track of the current frame number and > schedule the USB frame. (The USB frame consist of isochronous, interrupt, > control, and bulk transactions, in that order) If the 1MS is slowed down, > the isochronous or interrupt transactions may not schedule correctly. > > Hopefully this answers your question.. > > Pei > > -----Original Message----- > From: Thomas Chen <[EMAIL PROTECTED]> > To: [EMAIL PROTECTED] > <[EMAIL PROTECTED]> > Date: Tuesday, January 14, 2003 9:05 PM > Subject: [linux-usb-devel] is 1 ms SOF interrupt ABSOLUTELY necessary??? > > >i am working on an embeded system using SL811 > > > >the 1MS interrupt is just eating up all the cpu cycle > >(by the way, can any one provide some input on MINIMUM cpu horse > >power needed to operate USB???) > > > >the question is whether it is possible to slow down this > >interrupt, say to 5 MS instead of 1 MS??? > > > >dont know much about the other part of the drivers... would it > >hurt? > > > >thanks a lot > > > > > > > > > >------------------------------------------------------- > >This SF.NET email is sponsored by: Take your first step towards giving > >your online business a competitive advantage. Test-drive a Thawte SSL > >certificate - our easy online guide will show you how. Click here to get > >started: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0027en > >_______________________________________________ > >[EMAIL PROTECTED] > >To unsubscribe, use the last form field at: > >https://lists.sourceforge.net/lists/listinfo/linux-usb-devel ------------------------------------------------------- This SF.NET email is sponsored by: Take your first step towards giving your online business a competitive advantage. Test-drive a Thawte SSL certificate - our easy online guide will show you how. Click here to get started: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0027en _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
