[ECOS] Problems using EP7212's SRAM on Cirrus Logic EDB7209

Hoss, Laurent hossl@student.ethz.ch
Wed Feb 7 03:31:00 GMT 2001


We badly need to use the 38K onchip-SRAM for our MP3-Decoder to work in
real time. Currently the decoder allocates 22K dynamically on EDB7209's
DRAM which seems to be much too slow.
( we have tried to port the new, very nice, open source MAD-Decoder
http://www.mars.org/home/rob/proj/mpeg/ )

So I simply tried to replace malloc's return value by 0x60000000
(SRAM-Addr).
Did not work. Therefore I made a test-loop which writes over the whole
SRAM.
Result: Only the first 4K returned the value which was written in. Above
that 4K only 0x00000010 was read.

First I tried to apply the patch to hal_platform_setup.h from the
posting
" http://sources.redhat.com/ml/ecos-discuss/2000-08/msg00156.html "
But that did not work (unable to apply hunk 2...).
Therefore I downloaded v1.8 (with the correct SRAM-size from
25.Aug.2000) of hal_platform_setup.h from CVS, and recompiled ecos (only
v.1.3.1, as the new Config.tool did not work with Windows 95).

Unfortunately the 4K problem remains :(

Another question: Would it be possible to have the whole prg + ecos only
in SRAM ?


Thank you 

Laurent Hoss


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