On Tue, Nov 2, 2010 at 1:57 PM, Christopher Head wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Mon, 1 Nov 2010 07:06:44 -0500 > "Olin Lathrop" wrote: > > [snip] >> You seem to be over thinking this. =A0Is there any reason to believe >> that setting STALL doesn't have the overall desired effect? =A0If you >> get a packet with the wrong toggle, then something else is already >> wrong. =A0Does it really matter which the SIE sends back for that? >> Presumably the next packet will have correct toggle and stall will be >> sent back. > > Well, in the interests of bullet-proof development, I thought that if > DTSEN takes precedence over BSTALL, you could set DTSEN=3D1, DTS=3D0, > BSTALL=3D1 on an OUT BD to handle the status stage of a control transfer > with an inbound data stage. Since the status stage should always > consist of a zero-length OUT transaction with a DATA1 packet in it, > this would mean a legitimate status stage would mismatch DTS and get > ACKed, whereas a host refusing to follow the rules and sending a DATA0 > instead would match DTS and get STALLed. > It is not that clear for your last sentence. Take note that "The host is not permitted to return a STALL under any condition" -- USB 2.0 Spec, Section 8.4.5. --=20 Xiaofan --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .