Hi --
--- In "jeremfg" <> wrote:
>
> Well, I've tried upgrading the origianl 1.0 Amp power supply with a 2.5 Amp
> power supply... It didn't solved the issue... And since the new one was more
> thand the double of the previous one, I'm pretty sure I'm well over the
> "edge" :P
>
> As for the coding style, I'm well aware there's a much better way, but since
> it isn't really an issue in our small project, and most of all, much simpler,
> there aren't any reason for me to upgrade. And mostly, since I'm a student in
> computer engennering, I'm kinda lacking this kind of knowledge too. And it's
> my theacher that has been doing it this way in the beggining!
>
>
> I've also looked at the errata on this specific CPU, but it's revision
> specific, and both (32 & 64 mb) card have the same E2 revision, so they would
> both be bothered by the SPI errata!
>
> I'm still out of ideas!
Does it change if you artificially limit memory to 32M on the kernel command
line when booting the 64M board? ("mem=32M" when booting). Also read up on
"memmap= xxx" command line option, if it's in your kernel version.
I doubt it would change anything, but you never know.
regards, ......... Charlie
> --- In "Breton M. Saunders" <breton.saunders@> wrote:
> >
> > Check for power supply problems. Although unlikely, you could be
> > running your power supply on the edge - problems wouldn't appear on the
> > 32Mb version, but the 64Mb version with slightly higher power
> > requirements could just push you over the edge.
> >
> > Otherwise, there shouldn't be any differences between the 64/32 mib
> > versions with regard to SPI connected devices.
> >
> > One question though: You have written a kernel driver to talk to the the
> > SPI display device right? This idea that writing to hardware using
> > user-mode code is completely brain-dead - you have no control over
> > timing problems, interrupts, or for that matter any access to the
> > features that the linux kernel provides you for device driver management.
> >
> > -Brett
> >
> > jeremfg wrote:
> > > Hi!
> > >
> > > We are currently trying to use the serial Digilent PmodCLS LCD with the
> > > SPI bus on a TS-7400 64mb version. The PmodCLS is a serial LCD including
> > > it's own microchip, so we only need to send ASCII characters on the SPI
> > > bus, and everything else is handled by the LCD.
> > >
> > > PmodCLS ->
> > > http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,401,473&Prod=PMOD-CLS
> > >
> > > Currently, it's working really fine with the 32mb version of the card, we
> > > can write on the CPU's registers of the SPI bus, and everything shows up
> > > fine on the LCD...
> > >
> > > However, as soon as we move to the 64mb version of the card, there is
> > > some messup... Even though the card seems indentical, same CPU and
> > > everything else seems identical except for the extra memory chip, it
> > > doesn't work well...
> > >
> > > I can assure you that the issue is hardware related... We've also tryed
> > > using the same SD card with the exact same OS on the 32-bit and 64-bit
> > > version...
> > >
> > > half the times, it simply does nothing on the LCD, the other half is
> > > splitted in two... some time writing the last character of the string I
> > > was sending, or in the second case, the last character of the last
> > > attempt followed by the first character of the current attempt....
> > >
> > > Never more than two characters, and it seems really slow in execution,
> > > compared to the 32mb version. Looking on an oscilloscope, we can clearly
> > > see that the LCD obey what it is sent... Only one, two or zero characters
> > > are sent, electrically, to the LCD so it isn't the issue!
> > >
> > > So, Is there any difference at all between the 32Mb version and the 64Mb
> > > version that isn't visible to the naked eye?
> > >
> > > Or does anyone have an hypothesis on what the problem could be?
> > >
> > > All I know, is that I base my C code on the temp_sensor example, and
> > > followed the documentation of the CPU thoroughly for initialisation and
> > > operation
> > >
> > > Any help would be greatly welcome!
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
>
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