Hi, On Wed, Sep 30, 2015 at 12:24:24AM +0200, Stefan Brüns wrote: > USB low/full speed allows for frequency tolerance of 1.5%/0.25%. At > maximum packet size (sync + PID + data + CRC16) of 12 bytes/1027 bytes > this amounts to 1.4 bits/20 bits, so the decoder has to lock to the > actual symbol frequency to avoid any symbol misdetections. > > The signal is sampled twice, once at the symbol center and once at > the expected edge position. Comparing the symbol at both positions gives > an indication if the current bit width is to low or to high. Adjust > accordingly.
Looks great. Merged, thanks! I also updated the tests in the sigrok-test repo accordingly. Could you please add your test file(s) and a small README to sigrok-dumps (and extend the tests in sigrok-test) as well, just to have some more data points and examples? Cheers, Uwe. -- http://hermann-uwe.de | http://randomprojects.org | http://sigrok.org ------------------------------------------------------------------------------ _______________________________________________ sigrok-devel mailing list sigrok-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sigrok-devel
