[vdr] Re: Increasing SDRAM on DVB cards

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Hermann Gausterer wrote:
> 
> > Hermann Gausterer wrote:
> > >
> > > ...
> > > the scs2 is allready routed to the osd ram chip ... i hope the
> > > HY57V161610D is the one used for OSD and not the other
> > > but i read today somewhere which chip is used for what
> >
> > I don't think so. Look a little closer at page 20 of the AV7110
> > data sheet. CC000000-CC1FFFFF is the range of the existing 2MB
> > of SDRAM, and in _that_ range there is some OSD memory allocated
> 
> yep i see this, but this is not an absolut, but insteed an relativ value
> on the top it says "SIZE" .. calc the adresses on the left to get
> the real values ;-)
> 
> you told me yourself that the av7110 uses two chips, one for OSD
> and one for A/V .. that does absolutly match the doku .. and it
> says clearly that the OSD ram chip is selected with the
> mystical SCS2 ;-)

I don't recall that. There _are_ two RAM chips, one is (slow) DRAM
and the other is (fast) SDRAM. The SDRAM is used for all the video
stuff, amoung which is OSD. But the video buffer and OSD memory is
absolutely, positively in the ONE and ONLY 2MB SDRAM chip! I don't
see anywhere where SCS2 would be used, because there is no second
SDRAM chip that it could address (I wish there was!).

> > (see the middle of the drawing). The actual sizes of each memory
> > area (B-Frame, OSD, Video- and Audio-Buffer) can be set at runtime,
> > and that's where the firmware has traded OSD memory for Video-Buffer
> > memory several times in the past.
> 
> no .. on the graph, OSD is always above CC20:0000 and so on,
> on chip 2 !

THERE IS NO (SDRAM) CHIP 2 ON THE EXISTING DVB CARDS!!!
(sorry for getting loud). The graph on page 20 indicates the range above
CC200000 as "Expansion Memory Area" which, amoung other things, *CAN*
be used for OSD. The current OSD memory is located in the lower range
(see CC153100-CC1AA1FF: "OSD or other use") of the ONE AND ONLY SDRAM
chip there is on the DVB card.

> > The remark "(OSD/User Data)" just tells us what that memory area
> > can be used for, but right now, since that memory isn't physically
> > there, the only OSD memory we have is in the lower 2MB of SDRAM.
> 
> you told me that there are two chips .. how does this fit togehter?
> for what is the other 2mb chip for? it can not be connected anywhere
> else on the av7110 !

The other chip is a (slow) DRAM chip which is used for several other
things that don't need that high performance (like regular data heap
etc). The OSD and video buffer stuff need fast RAM, and that's why all
this is located in the SDRAM chip. As you can see on page 13 the DRAM
memory area is mapped to 2E000000-2FFFFFF (of course, only 2MB are
present).

Klaus
-- 
_______________________________________________________________

Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
_______________________________________________________________


-- 
Info:
To unsubscribe send a mail to ecartis@linuxtv.org with "unsubscribe vdr" as subject.