[LinuxBIOS] Fun easy question. 512Kb or 256Kb

Adam Talbot talbotx at comcast.net
Tue Feb 7 08:51:31 CET 2006

-Peter Stuge
Cool, that is great info to know.  Both of my chips are 45-4C-NH.
45 Msec
4=10,000 write cycles (doc, thank you for the link)
PLCC, 32

Is there any thing from the Linuxbios side of the world, besides the 
size config? 
Does Linuxbios load the whole chip into ram(so 256k or 512k), or just 
it's self on startup?

Speed in ns:
What controls that? Can I set/change the access speed to my "bios chip"?
I have a few boards that had Eon chips(120ns), I have replaced them with 
SST's(45ns), they work fine.  Are they running faster? 
On this current project all I care about is boot time and ever 0.10 
seconds I can save, counts.

Peter Stuge wrote:

>On Mon, Feb 06, 2006 at 10:41:02PM -0800, Adam Talbot wrote:
>>Fun easy question. 
>>Messing about with my new board, and have an easy question.  So I have 
>>both the SST 39SF020 and the 39SF040 flash chip. My payload is just 
>>filo; so I can fit Linuxbios on the 256Kb or the 512Kb flash chip. Is 
>>there any reason to use the 512Kb?
>>Faster, slower, any thing else like that?
>It depends on the second line of numbers on the package.
>SST 39SF0x0(A) is on the first line
>45-4C-NH(E) or something similar is on the second line
>45/70 is read access speed in ns
>4 is minimum life in write cycles
>C is temperature range (Commercial 0c->70c or Industrial -40c->85c)
>N is PLCC
>H is 32 leads
>E is lead-free
>Page 20 of http://www.sst.com/downloads/datasheet/S71147.pdf
>But, I doubt you would even be able to measure difference in speed
>between 45 and 70 ns versions. :)

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