8051 data compression

A recent article in Circuit Cellar (November 2004), mentions just that,
includingdetails of the compression algorithm used.

ted

Martin wrote:
> I should have been more precise.  Trying to consider compressing a Virtex II 
> bitfile.  Storage would be in an external SPI FLASH device.  The 
> uncompressed bit image is just under 512K-bytes.  In looking at it, there 
> are lots of 0x00 bytes.  It should compress very well.
> 
> Lossy compression is not an option, obvisouly.
> 
> -Martin
> 

Doesn't the Virtix II support compressed bitstreams?  I've never used 
Xilinx devices myself, but Altera devices all support compression in the 
devices themselves.  Trying to further compress the compressed 
bitstreams is a waste of effort, as you are never going to get better 
than a percent or two.  Also, if you are using encrypted bitsteams, you 
are not going to be able to compress them effectively.

> Doesn't the Virtix II support compressed bitstreams?

Yes.  However, the form of compression they use is to match repeating 
frames, which isn't ideal in non-trivial designs.  Almost anything else 
should produce better results.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Martin Euredjian

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Hi Dear:
Keil developmmet environmnet give you 56 bit 8051 compression sample for
free.
Look there, I porteed 128 rigandel public domain algorithms. It took 28k ram

"Martin" <0_0_0_0_@pacbell.net> wrote in message
news:17pdf.26091$6e1.2999@newssvr14.news.prodigy.com...
> Looking for lightweight data compression code for the 8051.  Preferably in
> C.  Can anyone offer links to pursue?  Speed is not all that important,
code
> size is.
>
>
> Thanks,
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Martin Euredjian
>
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