NE64 with a slowest external memory (NVRAM).

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NE64 with a slowest external memory (NVRAM).

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NeoSP
Contributor I
Dear friends,
 
I'm getting a big trouble with NE64 using a NVRAM as SRAM. How everybody knows, the NVRAM is slowest than SRAM. The NVRAM I'm using has a access time of 120ns, but I have to use a bus clock in 16MHz because I have to setup the SCI baud rate in 62500.
Could anybody help me to solve that? How could I use a NVRAM (Tac=120ns) with a bus clock in 16MHz? Is there any solution or idea for that?
 
Thanks in advance.
Neo.

Message Edited by NeoSP on 2007-02-0411:42 PM

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Alban
Senior Contributor II
Hello and Welcome Neo,
 
With S12, you have the Clock Stretch possibility, look at the External Bus Interface (EBI) datasheet.
If the stretching to 8 cycles is not enough, I remember there is a WAIT (or EWAIT) possibility to wait on the external device like your memory.
 
May you please have a look and come back to the Forum if you need more assistance ?
 
Cheers,
Alban.
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NeoSP
Contributor I

Dear Alban,

Thanks for your help, but in my case, using the NE64, sinceresly, I didn't found EWAIT mode and the clock stretch, the number 3 is the maximum value allowed, but it's not enough.

Can I use some device, like an IC, in that I can stretch this pulse through of the hardware? Do you think that it will run?

 

Thanks in advance,

Best regards,

Marco.

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