Mixing 12 nS memory with 15 nS memory

      I have a Zilog development system (the Acclaim) and I 
need to add some SRAM.  I'm running into a lot of problems 
finding  3 pcs. of 12 nS, 512K x 8 memory, so I would like 
to know if anyone has had problems mixing 12 nS with 15 nS 
SRAM.
      It looks like 15 nS memory should work because there 
is an added cycle (20 nS) anyway, but I'm hesitant to go 
forward unless I know that this has been tried and works. 
If the chips were cheap and I could stick them into a DIP 
socket (days gone by), then the question would be moot.

Thanks,
Dennis
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On Mon, 29 Mar 2004 16:41:04 GMT, D. Zimmerman wrote:
>       I have a Zilog development system (the Acclaim) and I 
> need to add some SRAM.  I'm running into a lot of problems 
> finding  3 pcs. of 12 nS, 512K x 8 memory, so I would like 
> to know if anyone has had problems mixing 12 nS with 15 nS 
> SRAM.
>       It looks like 15 nS memory should work because there 
> is an added cycle (20 nS) anyway, but I'm hesitant to go 
> forward unless I know that this has been tried and works. 
> If the chips were cheap and I could stick them into a DIP 
> socket (days gone by), then the question would be moot.

I went to Digikey and saw the 15ns SRAMs and also went to
Newark ( http://www.newark.com/ ) and did a search on as7c34096 and
came up with $22.48 ea ($5 handling fee plus Shipping).

Try this:

http://www.newark.com/NewarkWebCommerce/newark/en_US/support/search/searchResults.jsp?action=0&First=0&QText=as7c34096&x=0&y=0


-- 
Linux Home Automation         Neil Cherry        ncherry@comcast.net
http://home.comcast.net/~ncherry/               (Text only)
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http://hcs.sourceforge.net/                     (HCS II)

      Thanks Neil.  The cost is one of the reasons for my 
question.  I need three of these, and the 15 nS parts are a 
lot cheaper, and I believe Digikey has them.
      That said, I think I may have found a source for three 
Cypres parts that are equivalent, and at about $10 each. 
Took a lot of digging though.

Dennis,

Neil Cherry wrote:

> On Mon, 29 Mar 2004 16:41:04 GMT, D. Zimmerman wrote:
> 
>>      I have a Zilog development system (the Acclaim) and I 
>>need to add some SRAM.  I'm running into a lot of problems 
>>finding  3 pcs. of 12 nS, 512K x 8 memory, so I would like 
>>to know if anyone has had problems mixing 12 nS with 15 nS 
>>SRAM.
>>      It looks like 15 nS memory should work because there 
>>is an added cycle (20 nS) anyway, but I'm hesitant to go 
>>forward unless I know that this has been tried and works. 
>>If the chips were cheap and I could stick them into a DIP 
>>socket (days gone by), then the question would be moot.
> 
> 
> I went to Digikey and saw the 15ns SRAMs and also went to
> Newark ( http://www.newark.com/ ) and did a search on as7c34096 and
> came up with $22.48 ea ($5 handling fee plus Shipping).
> 
> Try this:
> 
> http://www.newark.com/NewarkWebCommerce/newark/en_US/support/search/searchResults.jsp?action=0&First=0&QText=as7c34096&x=0&y=0
> 
> 


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"D. Zimmerman" <7UPdzimmerman@stny.rr.com> wrote in message news:<AkY9c.60648$Oo5.38672@twister.nyroc.rr.com>...
> I have a Zilog development system (the Acclaim) and I 
> need to add some SRAM.  I'm running into a lot of problems 
> finding  3 pcs. of 12 nS, 512K x 8 memory, so I would like 
> to know if anyone has had problems mixing 12 nS with 15 nS 
> SRAM.
>       It looks like 15 nS memory should work because there 
> is an added cycle (20 nS) anyway, but I'm hesitant to go 
> forward unless I know that this has been tried and works. 
> If the chips were cheap and I could stick them into a DIP 
> socket (days gone by), then the question would be moot.

If you do a simple timing analysis, you'll know whether or not the
slower devices will work.

-a

Andy Peters wrote:
> "D. Zimmerman" <7UPdzimmerman@stny.rr.com> wrote in message news:<AkY9c.60648$Oo5.38672@twister.nyroc.rr.com>...
> 
>>I have a Zilog development system (the Acclaim) and I 
>>need to add some SRAM.  I'm running into a lot of problems 
>>finding  3 pcs. of 12 nS, 512K x 8 memory, so I would like 
>>to know if anyone has had problems mixing 12 nS with 15 nS 
>>SRAM.
>>      It looks like 15 nS memory should work because there 
>>is an added cycle (20 nS) anyway, but I'm hesitant to go 
>>forward unless I know that this has been tried and works. 
>>If the chips were cheap and I could stick them into a DIP 
>>socket (days gone by), then the question would be moot.
> 
> 
> If you do a simple timing analysis, you'll know whether or not the
> slower devices will work.
> 
> -a
Andy,
      That is what I meant when I said "It looks..."  What I 
wanted to hear is that someone actually did that with no 
problems.  My concern is that there are a lot of things that 
should work, but for some reason they don't.  This is 
especially true when a part from another vendor is used.

Dennis,

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