Herbert: Yes, I did, thank you for your comment. I checked twice, the pins SEL1,SEL2 are both grounded, which indicates 8080 mode. I will check again to double check. The reference design that I am using here originally had a NOT gate for the WR/RD signals so that they were always opposite each other, and then combined with an OR gated with CS (so WR/RD could only ever go low if CS was also low). I have since removed these chips because I thought that they were causing part of the problem, but the behaviour is the same no matter what. Maybe I'll try forcing it to 6800 mode and see if it works any different. Maybe I need to add a decoupling cap close to SEL1 or something. Come to think of it, why are there 2 SEL pins if both configurations have SEL2 tied low? Thanks for the suggestions. -- Sean At 12:09 2/16/2006, you wrote: >Sean, > >did you read my comment about the 6800 and 8080 mode - resp. did you check >if you are running the correct mode? > >Herbert > >At 12:04 16.02.2006 -0500, you wrote: > > >Thanks for the comment Glen, > > > >I checked the timing with an Oscilloscope and it's fine. The pulses stay > >for about 500nS (I'm using legacy GPIO mapping so it's slower). A complete > >write cycle takes 940nS. If anything I think it may be too slow, but I've > >seem this used with a 8051 (much slower) without any issues, unfortunately > >I don't have the source code for that. Maybe I'll try using FGPIO and see > >if that makes a difference. > > > >Does anyone know of any alternatives to SED13305 (that's cheap?) > > > >Thanks! > > > >-- Sean > > > >At 07:15 2/16/2006, you wrote: > > >Sean, > > > > > >I have used the SED 1335 in the past. One thing that is too > > >obvious is that the SED part is probably not the fastest thing > > >in the world, and you may be exceeding it speed capability. > > > > > >I never had this problem with the Z80 family I was using at the > > >time, but the new ARM chips are way too fast for the 1335, I do not > > >know about the chip you are using. > > > > > >Just a thought. > > > > > >Glen > > > > > > > > >Sean wrote: > > > > > > > Hello all, > > > > > > > > I am having an issue here and I hope someone has some suggestions. I'm > > > > trying to interface some LCDs to my micro, I have a graphical 128x64 > > which > > > > has an embedded controller chip interfaced fine, using P1.16-P1.23 as > > > 8-bit > > > > parallel IO. However when I try to hook up a SED13305 the data > seems to > > > > get corrupted. I'll issue a write to the device to store something in > > > > VRAM, then immediately try to read it back. Here's where things get > > weird. > > > > > > > > If I try to use the WR and RD signals like they should be used (RD > always > > > > high, Clear WR, Set Byte, Set WR), the write appears to work, however > > > > repeated reads of the same memory area return different results each > > > > time. Enough reads show that the data was written > successfully. However > > > > if I modify only the write routine to use the WR and RD signals in a > > > > different (wrong) way (Clear WR, Set RD, Set Byte, Set WR, Clear > RD) then > > > > repeated reads return the same data every time, however bits 7:8 are > > > always > > > > "10". Note that the read routine is the exact same both times. > > > > > > > > How is it possible to have a small change to the write routine > effect how > > > > the read routine works? > > > > > > > > I have tried playing with timing to no avail. I looked at everything > > with > > > > an oscilloscope and the timing and data look correct. I've > verified all > > > > connections with a multimeter. I have both the micro and the SED > running > > > > off of 3.3V. Note that if the SED is running at 5V then I get complete > > > > garbage on read (meaning probably nothing worked), even though the SED > > > says > > > > it works from 2.7V to 5.5V. > > > > > > > > I think I'm going to have to try to make another test board, but > before I > > > > run out to do that does anyone have any ideas as to why this is > > happening? > > > > > > > > Thanks, > > > > > > > > -- Sean > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >SPONSORED LINKS > > ><<<http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontrol > ler>http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontroller > > > s&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ><http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ>http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ>Microcontrollers > > > > > ><<<http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrolle > rs&>http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers& > > > w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA><http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA>http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA>Microprocessor > > > > > ><<<http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microco > ntr>http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontr > > > ollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw><http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw>http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw>Intel > > > > > >microprocessors > > ><<<http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcon > tro>http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontro > > > llers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw><http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw>http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw>Pic > > > > > >microcontrollers > > > > > > > > >---------- > > >YAHOO! GROUPS LINKS > > > > > > * Visit your group > > > "<<<http://groups.yahoo.com/group/lpc2000>http://groups.yahoo.com/group/lpc2000>http://groups.yahoo.com/group/lpc2000>lpc2000" > > > > > > on the web. > > > * > > > * To unsubscribe from this group, send an email to: > > > * > > > > > > <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe>lpc2000-unsubscribe@yahoogroups.com > > > > > > > > > * > > > * Your use of Yahoo! Groups is subject to the > > > > > > <<<http://docs.yahoo.com/info/terms/>http://docs.yahoo.com/info/terms/>http://docs.yahoo.com/info/terms/>Yahoo! > > > Terms of Service. > > > > > > > > >---------- > > > > > > > >SPONSORED LINKS > ><<http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontroller > s&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ>http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ>Microcontrollers > > ><<http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers& > w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA>http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA>Microprocessor > > ><<http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontr > ollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw>http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw>Intel > > >microprocessors > ><<http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontro > llers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw>http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw>Pic > > >microcontrollers > > > > > >---------- > >YAHOO! GROUPS LINKS > > > > * Visit your group > "<<http://groups.yahoo.com/group/lpc2000>http://groups.yahoo.com/group/lpc2000>lpc2000" > > > on the web. > > * > > * To unsubscribe from this group, send an email to: > > * > > > <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe>lpc2000-unsubscribe@yahoogroups.com > > > > > * > > * Your use of Yahoo! Groups is subject to the > > > <<http://docs.yahoo.com/info/terms/>http://docs.yahoo.com/info/terms/>Yahoo! > Terms of Service. > > > > > >---------- > >---------------------------------------------------------- >demmel products >Radnitzkygasse 43 >A-1100 Vienna / Austria / Europe >Voice: +43-1-6894700-0 >Fax: +43-1-6894700-40 >Email: dh@... >WWW: <http://www.demmel.com>http://www.demmel.com > > >[Non-text portions of this message have been removed] > > > >SPONSORED LINKS ><http://groups.yahoo.com/gads?t=ms&k=Microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=mfaAujKZXA2Z_vxre9sGnQ>Microcontrollers ><http://groups.yahoo.com/gads?t=ms&k=Microprocessor&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=9jjd2D3GOLIESVQssLmLsA>Microprocessor ><http://groups.yahoo.com/gads?t=ms&k=Intel+microprocessors&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=OMnZuqMZX95mgutt4B-tDw>Intel >microprocessors ><http://groups.yahoo.com/gads?t=ms&k=Pic+microcontrollers&w1=Microcontrollers&w2=Microprocessor&w3=Intel+microprocessors&w4=Pic+microcontrollers&c=4&s=95&.sig=Malspbd0T4Rq3M4Q0nHrfw>Pic >microcontrollers > > >---------- >YAHOO! GROUPS LINKS > > * Visit your group "<http://groups.yahoo.com/group/lpc2000>lpc2000" > on the web. > * > * To unsubscribe from this group, send an email to: > * > <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe>lpc2000-unsubscribe@yahoogroups.com > > * > * Your use of Yahoo! Groups is subject to the > <http://docs.yahoo.com/info/terms/>Yahoo! Terms of Service. > > >----------
Message
Re: [lpc2000] Problem LPC2148<->SED13305 (anyone know alternatives?)
2006-02-16 by Sean