[ECOS] EDB7212 LCD support

[ECOS] EDB7212 LCD support

[Fano Ramparany]

Has anybody extended the LCD support provided in eCos 1.3.1 for Cirrus
Logic
EDB7212 board to display grey level images on the screen?
This is not specific to eCos, but I don't know other mailinglists
dedicated to
EDB72XX board developments.

Fano Ramparany

Re: [ECOS] EDB7212 LCD support

[Lewin A.R.W. Edwards]

Hi Fano,

>Has anybody extended the LCD support provided in eCos 1.3.1 for Cirrus
>Logic EDB7212 board to display grey level images on the screen?

Where did you find information on how to use the LCD support at all? 
Basically the only info I've found is a note in the configuration utility 
that says that enabling LCD support allocates 128K of RAM. Thus far I have 
no idea where that RAM is, is there a symbol that points to it?

I presume that the way to get grayscale is to enable LCD support (which 
allocates the full 128K of RAM for the LCD frame buffer) then manually poke 
the LCD controller registers for the desired LCD size and bit depth.

Our system is driving a 320x240 color display, which is effectively a 960 x 
240 grayscale display, so I will have to solve the same problem myself.


Lewin A.R.W. Edwards (Embedded Engineer)
Got any Commodore 16 or VIC-20 hardware, cartridges, tapes?
Visit http://www.larwe.com/vintage/
================================================
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

Re: [ECOS] EDB7212 LCD support

[Gary Thomas]

On 29-Nov-2000 Lewin A.R.W. Edwards wrote:
> Hi Fano,
> 
>>Has anybody extended the LCD support provided in eCos 1.3.1 for Cirrus
>>Logic EDB7212 board to display grey level images on the screen?
> 
> Where did you find information on how to use the LCD support at all? 
> Basically the only info I've found is a note in the configuration utility 
> that says that enabling LCD support allocates 128K of RAM. Thus far I have 
> no idea where that RAM is, is there a symbol that points to it?
> 
> I presume that the way to get grayscale is to enable LCD support (which 
> allocates the full 128K of RAM for the LCD frame buffer) then manually poke 
> the LCD controller registers for the desired LCD size and bit depth.
> 
> Our system is driving a 320x240 color display, which is effectively a 960 x 
> 240 grayscale display, so I will have to solve the same problem myself.

Look at the sources.  There are sample/test programs for the LCD which show
you how to set it up for the 320x240 grayscale LCD that comes standard with
the Cirrus Logic eval boards.  The rest is up to you and the documentation.

Re: [ECOS] EDB7212 LCD support

[Fano Ramparany]

Lewin,

Basically there is a mapping between the LCD frame buffer
and a predefined portion of the RAM, which lets you write/read
in the LCD frame buffer as if you write/read in the RAM.
This mechanism is clearly described in the Cirrus Logic
Datasheet DS474PP1 that they ship you with the board in the
section 3.14 "LCD controller with support for on chip frame
buffer" at page 46 . There is also a description of how you could
program the LCD controller (screen dimensions, nb. of bits
per pixel, refresh rate,...) in section 3.14 "LCD Registers" at
page 79.

The eCos lcd_support.c file can be found in
...\RedHat\eCos\package\hal\arm\edb7xxx\v1_3_1\misc

I've done a quick (not dirty yet;-) extension for
displaying greylevel images I can send you if you want.

Fano


"Lewin A.R.W. Edwards" wrote:

> Hi Fano,
>
> >Has anybody extended the LCD support provided in eCos 1.3.1 for Cirrus
> >Logic EDB7212 board to display grey level images on the screen?
>
> Where did you find information on how to use the LCD support at all?
> Basically the only info I've found is a note in the configuration utility
> that says that enabling LCD support allocates 128K of RAM. Thus far I have
> no idea where that RAM is, is there a symbol that points to it?
>
> I presume that the way to get grayscale is to enable LCD support (which
> allocates the full 128K of RAM for the LCD frame buffer) then manually poke
> the LCD controller registers for the desired LCD size and bit depth.
>
> Our system is driving a 320x240 color display, which is effectively a 960 x
> 240 grayscale display, so I will have to solve the same problem myself.
>
> Lewin A.R.W. Edwards (Embedded Engineer)
> Got any Commodore 16 or VIC-20 hardware, cartridges, tapes?
> Visit http://www.larwe.com/vintage/
> ================================================
> Work: http://www.digi-frame.com/
> Personal: http://www.zws.com/ and http://www.larwe.com/

Re: [ECOS] EDB7212 LCD support

[Gary Thomas]

On 30-Nov-2000 Fano Ramparany wrote:
> I've done a quick (not dirty yet;-) extension for
> displaying greylevel images I can send you if you want.
> 

Or possibly share them with the list?  Depending upon circumstance,
we [the eCos team] can integrate them into the mainline or add the
files to our contributed area.