Depending on what you are up to you might want a completely different design...balenced lines and twisted pairs, do a Google search and some circuits should pop up * Micha?? Pleban (firstname.lastname@example.org) wrote: > Hello! > > Francesco Messineo wrote: > > > what kind of termination did you use? > > I tried a termination resistor. I used a potentiometer to try different > values from x Ohm to xxx Ohm, none had any visible impact. > > > What gate drives the signal? > > I believe it's a HMOS-II chip. > > > Is the power to the driver and receiver chip very well bypassed? > > I am not sure what that means :-( > > > if it's really an "interference" (the exact term here is crosstalk) > > between two signals, you have to run a GND wire between each two data > > (or clock or whatever else) wires. That's how original parallel SCSI > > and HPIB bus cables were made. Of course these busses are also *very* > > well terminated. > > That is a good idea, but it would mean I had to make my own cable > instead of using an off-the-shelf one. I can go there, but as a last resort. > > > It might be a termination issue or a bypassing issue likely. > > You should first try to add a 47 ohm resistor just before the cable > > beginning at the driver side, on every signal (but VCC if any and > > GND). > > Another good idea, but soldering resistors inside a C65 gives me chills > for some reason ;-) The receiver is also meant to work on a sock machine > without madifications. > > > The take a picture of the scope with AC coupling, gnd clip on gnd pin > > of the driver and probe tip on the VCC pin of the driver. The do the > > same on receiver chip. This will show you if there's any ground or > > power bounce (bad decoupling in this case). > > I will do that tomorrow, thanks. > > > Also, whenever you suspect a crosstalk issue, take a picture of both > > signals, not just one :) > > There are six signals in the cable, plus GND and reset. I am not sure > what crosstalks with what :-( > > Regards, > Michau. > > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2016-12-22 03:00:02
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