On Sun, 19 Oct 2008, Sebastian Kuzminsky wrote: > Date: Sun, 19 Oct 2008 15:49:18 -0400 > From: Sebastian Kuzminsky <[EMAIL PROTECTED]> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] hm2_7i43 hostmot2 loading - invalid cookie? > > Peter C. Wallace wrote: >> Can you verify that your parallel port supports and is configured for EPP >> version 1.9 (1.7 will _not_ work) >> >> After a little thinking, your symptoms (parallel port firmware load works but >> communication with FPGA fails) suggests the possibiolity that your EPP port >> is >> in 1.7 mode... > > I dont understand this. The difference between EPP 1.7 and 1.9 is that > in 1.7, a sender can start a new Data cycle before the receiver asserts > nWait indicating the end of the current cycle, but in 1.9 the sender has > to wait, right? yes > > I assume the 7i43 CPLD and HostMot2 both implement EPP 1.9, meaning they > always respect nWait when sending data.
Yes 1.9 is basically a full handshake > > If the BIOS sets the EPP controller on the PC to EPP 1.7 mode, then that > means that the PC might send data to the 7i43 faster than the 7i43 is > prepared to accept it (the PC would start the next Data cycle before the > 7i43 asserted nWait). > > It seems to me that this problem would be exacerbated if the PC had a > lot of data to send, such as during firmware loading. But firmware > loading is the one thing that seems to work (as evidenced by the /INIT > bit doing the right thing); it's the subsequent read from the 7i43 > that's problematic. But the read from the 7i43 should be controlled by > the EPP 1.9 compliant timing in the 7i43. The CPLD might work in 1.7 mode because its timing is faster, the FPGA is deliberately slower to allow maximal length cables (tested at 10 feet) > > What am I missing? > > > -- > Sebastian Kuzminsky > Distances obtained as the speed of light multiplied by a cosmological > time interval have no direct physical significance. > <http://en.wikipedia.org/wiki/Observable_universe> > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
