-----Original Message-----
>From: l... on behalf of madid87
>Sent: Mon 29/12/2008 23:03
>To: l...
>Subject: [lpc2000] Again LPC2478, LCD & External Bus Interface
>
>I know by now that it is not possible to execute from external FLASH
>memory and simultaneously drive an LCD.
>
>Now, this information is very important. Is it possible to execute
>from external SDRAM and drive an LCD with LCD frame buffer in SDRAM
>too without LCD flickering? Let's say LCD is 320x240 TFT.
>
>Thank you very much !
Sorry, coming slightly late here...
The above is not true any more. With a 320x240 TFT you'll be able to execute from external flash, or SDRAM, and drive the LCD no problem.
The flickering problem which some of us experienced only shows up with bigger TFTs (requiring a higher pixel clock rate), and anyway NXP have come up with a fix for it which I posted in this forum some weeks ago. So you should have no problems.

--
Tim Mitchell

What do you need to run in external memory? I've my own board with LPC2478, 32MB SDRAM and Casio QVGA panel. I don't have any problem with flickering. It looks like LCD controller has the highest priority for accessing external memory. I think it won't be easy to run ucLinux in SDRAM with LCD controller enabled and driving QVGA panel. It should work, but there is no cache for SDRAM access and it would be too slow. Try to set lower clocks in LCD_CFG or optimize EMC settings to get better preformance.

Michal

----- Original Message -----
From: madid87
To: l...
Sent: Wednesday, December 31, 2008 7:08 PM
Subject: [lpc2000] Re: Again LPC2478, LCD & External Bus Interface
--- In l..., "rtstofer" wrote:
> Of course, I'm not sure why anyone would want to run code out of SDRAM
> unless they were running something like uCLinux but what do I know?

Internal FLASH is to small for our application. Yes, we'll be running
RTOS like eCos or similar. Idea is to add only x32 SDRAM chip on the
board.

Thank you for your reply. I still don't know what is the answer to my
question :(

Happy new year,
Do you intend to display a movie on LCD? QVGA is quite small so many of them
has internal memory and you can access it's memory as a SRAM. There you
don't have to scan them continuously like when you use LCD controller.
Best Regards,
Chutiman Yongprapat
On Thu, Jan 1, 2009 at 1:08 AM, madid87 wrote:

> --- In l... , "rtstofer"
> wrote:
> > Of course, I'm not sure why anyone would want to run code out of SDRAM
> > unless they were running something like uCLinux but what do I know?
>
> Internal FLASH is to small for our application. Yes, we'll be running
> RTOS like eCos or similar. Idea is to add only x32 SDRAM chip on the
> board.
>
> Thank you for your reply. I still don't know what is the answer to my
> question :(
>
>
>

Here is a development platform that has a reasonable cost
http://www.sparkfun.com/commerce/product_info.php?products_id53

It comes with uBoot loaded in flash (I think) and source/binary for
uCLinux. 64MB of SDRAM seems like a lot plus it has and SD/MMC connector.

Pretty cheap, considering...

Richard

--- In l..., "madid87" wrote:
>
> --- In l..., "rtstofer" wrote:
> > Of course, I'm not sure why anyone would want to run code out of SDRAM
> > unless they were running something like uCLinux but what do I know?
>
> Internal FLASH is to small for our application. Yes, we'll be running
> RTOS like eCos or similar. Idea is to add only x32 SDRAM chip on the
> board.
>
> Thank you for your reply. I still don't know what is the answer to my
> question :(
>

It is in the nature of problem solving that you ask around and see
what others have done. But, if you don't get a suitable answer, you
are going to have to do the work and become the expert.

Get one of those LCD development boards and see how it works.

In fact, there's no reason not to design a basic PCB (or stackable set
of PCBs) and see how it comes out.

As you said, this is the ONLY chip that MIGHT work so it's not like
you have choices. It will either work or your app is toast.

Peraonally, I might look at Blackfin. It has a nice LCD interface and
there are prototype boards around like the BF537 STAMP. Yes, it's
only a 16 bit machine but it runs uCLinux just fine. I don't know if
you can run code from the LCD frame buffer. It never occurred to me
to try.

Nobody around here seems to be able to answer your question. You can
write to NXP or just get started. If I had it to do, I would get started.

I might also consider what it meant to use a separate frame buffer,
external to the LPC.

Richard

--- In l..., "rtstofer" wrote:
> Of course, I'm not sure why anyone would want to run code out of SDRAM
> unless they were running something like uCLinux but what do I know?

Internal FLASH is to small for our application. Yes, we'll be running
RTOS like eCos or similar. Idea is to add only x32 SDRAM chip on the
board.

Thank you for your reply. I still don't know what is the answer to my
question :(

--- In l..., Robert Adsett wrote:
>
> Robert Adsett wrote:
> > madid87 wrote:
> >> If I don't get an reliable answer what should I do, write to NXP
> >> support? Do they usually answer?
> >
> > You probably should.
> >
> > Also take a look through the archives. There was a discussion on
> > driving LCDs a while ago. I wasn't following it so I don't know
if it
> > is applicable.
>
> Search for "LPC2478 LCD controller" around mid december.
>
> Robert
>

There is certainly a lot of code at the referenced link:

http://www.standardics.nxp.com/support/design/microcontrollers/lcd.controller/

But I don't know that it directly responds to the OPs question re:
executing code from the same memory space.

Of course, I'm not sure why anyone would want to run code out of SDRAM
unless they were running something like uCLinux but what do I know?

Given that there are LCD development boards, it would be easy enough
to just test the idea. As the LCD can have the highest memory
priority, it SHOULD work but I suspect it depends on the actual LCD
interface and how it handles delays in memory fetch.

Richard

Robert Adsett wrote:
> madid87 wrote:
>> If I don't get an reliable answer what should I do, write to NXP
>> support? Do they usually answer?
>
> You probably should.
>
> Also take a look through the archives. There was a discussion on
> driving LCDs a while ago. I wasn't following it so I don't know if it
> is applicable.

Search for "LPC2478 LCD controller" around mid december.

Robert

madid87 wrote:
> If I don't get an reliable answer what should I do, write to NXP
> support? Do they usually answer?

You probably should.

Also take a look through the archives. There was a discussion on
driving LCDs a while ago. I wasn't following it so I don't know if it
is applicable.

Robert

An Engineer's Guide to the LPC2100 Series