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Video interface chip?

Video interface chip?

2002-06-21 by Micael Beronius

Hello everyone.

I have a design, where we recently decided to add support for a TFT
color display, and since most of them seems to have video in (ntsc or
pal) as their only interface, I'll need some video encoder in my
design. I'd like something like a video ram to put our data in, and
the chip then generates video signal from this, without too much CPU
intervention and it must not bee to expensive. The displays we are
looking at are something like 400*240 pixels. Now, there must be a
chip that does this for me!? Any suggestions?

Sorry for being a bit off topic..

P.S. the current design is based on a 68331.



 - Micael

RE: [68300] Video interface chip?

2002-06-21 by Posey, Douglas

Look at the Epson SED1375.  It is a single chip solution which incorporates the
LCD controller along with the video ram.  I believe it sells for around $15 in
1000 piece qty.  We use it with a 68376.

Doug
Show quoted textHide quoted text
-----Original Message-----
From: Micael Beronius [mailto:micael.beronius@...]
Sent: Friday, June 21, 2002 6:29 AM
To: 68300@yahoogroups.com
Subject: [68300] Video interface chip?



Hello everyone.

I have a design, where we recently decided to add support for a TFT
color display, and since most of them seems to have video in (ntsc or
pal) as their only interface, I'll need some video encoder in my
design. I'd like something like a video ram to put our data in, and
the chip then generates video signal from this, without too much CPU
intervention and it must not bee to expensive. The displays we are
looking at are something like 400*240 pixels. Now, there must be a
chip that does this for me!? Any suggestions?

Sorry for being a bit off topic..

P.S. the current design is based on a 68331.



 - Micael



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Re: [68300] Video interface chip?

2002-06-21 by Robert Yablonski

Micael,

I have just completed a design where I utilized Sharp LQ038 TFT LCD which 
is a 6 bit digital RGB TFT.  The interface controller chip is an Epson SED1376.

NTSC type LCD's are really RGB with separate NTSC to RGB converter cards 
attached.  The screens are optimized for display of movies in analog 
format.  NTSC has many bad artifacts the most notorious being limited 
capability for displaying characters, and has many problems with color 
bleed thru from one color to another.

Your display selection in the NTSC format is pretty much limited to those 
used in Aircraft seatback video applications or in SUV video 
applications.  The size selection is really small, 5.6" and 6.4".  Any 
other size is an RGB with custom designed interface circuits. To use these 
displays you have to take your digital data convert it from RGB to NTSC, 
then that gets converted back by the DISPLAY.  What a waste.

Unless you have done an NTSC design before plan on spending 9 to 14 months 
with a couple of people.  It is not a simple matter of a couple digital 
lines.  Stick with RGB, pick out the monitor first then ask those people 
for recommendations on interface chips.  My design required a full set of 
5V to 3.3V interface chips, the EPSON chip, a programmable oscillator, a 5V 
to +12V backlight DC to DC converter, then the LCD does not have a 
backlight inverter so had to add a LINFINITY backlight driver board.

Now here comes the kicker.  How are you going to display the data.  In my 
application I have to do pictures with overlayed text in up to 9 languages 
and have variable sized fonts.  Add 1 programmer and 12 months to figure 
all this out.  How much memory do you have?  Remember the 33x series is not 
a Windows machine with lots of graphics support, you will be doing every 
thing as pixels, one at a time.

Our customer has mounted the LCD with a bezel which covers a small portion 
of the active screen area.  Because the mechanical alignment cannot be 
perfect the screen is offset in X and Y by a random number of pixels from 
unit to unit.  I needed a software solution where the information could be 
moved on the screen to line up with the bezel for proper display on the screen.

If you have not worked with LCD's figure 3-4 people for the better part of 
a year before you have enough working hardware and software to do customer 
demo's.  If you have done these kind of designs, figure 2 people for the 
same period.

Good Luck

Robert E. Yablonski
Hunt Dabney & Associates
1366 Logan Ave
Suite B
Costa Mesa, CA 92626
714-540-2372 X104
yabo@...

Re: Video interface chip?

2002-06-21 by Aaron J. Grier

On Fri, Jun 21, 2002 at 12:28:57PM +0200, Micael Beronius wrote:

> I have a design, where we recently decided to add support for a TFT
> color display, and since most of them seems to have video in (ntsc or
> pal) as their only interface, I'll need some video encoder in my
> design.

going a little further down the supply chain, it's possible to drive an
LCD screen directly through a digital interface, which would give better
looking results.

> I'd like something like a video ram to put our data in, and the chip
> then generates video signal from this, without too much CPU
> intervention and it must not bee to expensive. The displays we are
> looking at are something like 400*240 pixels. Now, there must be a
> chip that does this for me!? Any suggestions?

having to drive NTSC really is a liability, though.  why not drive the
LCD directly if you can?  or at the very least go through a VGA
interface.

> Sorry for being a bit off topic..
> 
> P.S. the current design is based on a 68331.

we use SED1376 with 68331 here.  it's a dumb framebuffer, so the poor
CPU has to handle everything, but the whole video controller is memory
mapped, so at least it's easy to program.  we use nano-X / microwindows
for graphics library, and while it's a little rough around the edges,
I've found it to be very hackable and well architected.

-- 
  Aaron J. Grier  |   Frye Electronics, Tigard, OR   |  aaron@...

Re: Video interface chip?

2002-06-23 by vespaman_66

Great, thanks everyone!

All of you seems to have gone for some Epson solution, and this is 
exactly the kind of pointer I where after! I'll give my local Epson 
distributor a call tomorrow, since they looks to have a descent range 
of video controllers.

Also, going for the digital interface is also something to 
investigate, since there may be such an interface for the display 
that we've found (there are some mechanical form factor issues that 
really makes our selection small, and our volums are less than 
2k/year, so..)

Aaron, about nano-X: how hard was it to port? Did/do you use it with 
some linux variant, or with a regular embedded rtos (or wihtout os?)?
I'll read up a bit more on nano-X, since I really do not want to 
reinvent those "graphical wheels" :-) I assume it is endian-aware.

thanks,

 - Micael

--- In 68300@y..., "Aaron J. Grier" <aaron@f...> wrote:
> On Fri, Jun 21, 2002 at 12:28:57PM +0200, Micael Beronius wrote:
> 
> > I have a design, where we recently decided to add support for a 
TFT
> > color display, and since most of them seems to have video in 
(ntsc or
> > pal) as their only interface, I'll need some video encoder in my
> > design.
> 
> going a little further down the supply chain, it's possible to 
drive an
> LCD screen directly through a digital interface, which would give 
better
> looking results.
> 
> > I'd like something like a video ram to put our data in, and the 
chip
> > then generates video signal from this, without too much CPU
> > intervention and it must not bee to expensive. The displays we are
> > looking at are something like 400*240 pixels. Now, there must be a
> > chip that does this for me!? Any suggestions?
> 
> having to drive NTSC really is a liability, though.  why not drive 
the
> LCD directly if you can?  or at the very least go through a VGA
> interface.
> 
> > Sorry for being a bit off topic..
> > 
> > P.S. the current design is based on a 68331.
> 
> we use SED1376 with 68331 here.  it's a dumb framebuffer, so the 
poor
> CPU has to handle everything, but the whole video controller is 
memory
> mapped, so at least it's easy to program.  we use nano-X / 
microwindows
> for graphics library, and while it's a little rough around the 
edges,
Show quoted textHide quoted text
> I've found it to be very hackable and well architected.
> 
> -- 
>   Aaron J. Grier  |   Frye Electronics, Tigard, OR   |  aaron@f...

RE: [68300] Video interface chip?

2002-07-01 by Peter Manser

Hi

Look at http://www.fs-net.de
They have several graphic board available.

We use DCU L3C and L4C with a 68332.


Peter 
Show quoted textHide quoted text
> -----Original Message-----
> From: Micael Beronius [mailto:micael.beronius@...]
> Sent: Freitag, 21. Juni 2002 12:29
> To: 68300@yahoogroups.com
> Subject: [68300] Video interface chip?
> 
> 
> 
> Hello everyone.
> 
> I have a design, where we recently decided to add support for a TFT
> color display, and since most of them seems to have video in (ntsc or
> pal) as their only interface, I'll need some video encoder in my
> design. I'd like something like a video ram to put our data in, and
> the chip then generates video signal from this, without too much CPU
> intervention and it must not bee to expensive. The displays we are
> looking at are something like 400*240 pixels. Now, there must be a
> chip that does this for me!? Any suggestions?
> 
> Sorry for being a bit off topic..
> 
> P.S. the current design is based on a 68331.
> 
> 
> 
>  - Micael
> 
> 
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