Async v.s. Sync RAM and SBSRAM

[Davy]

Hi all,

I notice that the difference with Asynchronous and Synchronous is
Synchronous
RAM is more faster? But why not all produce Synchronous RAM?

And what's SBSRAM's "Burst" mean? Is the data rate burst?
What's difference with common SRAM and SBSRAM?

Any suggestions will be appreciated!
Best regards,
Davy

 

[PeteS]

Synchronous RAM requires an external clock, whereas asynchronous RAM
does not. Sync RAM can certainly be faster, but not all designs need
sync RAM. Async RAM is generally much easier to design in a system.

SyncBurst (which is a registered trademark of Micron, I believe) is for
those sync RAMs where 'n' back to back writes or reads are done for a
single command cycle.

In this case, the cycle starts with a command (write or read), and then
'n' (usually 2 or 4) reads or writes are automatically completed. That
gives a high burst throughput.

For more details about sync ram in general, see this marketing blurb:

http://download.micron.com/pdf/pubs/buyersnews/bn501.pdf

For specific information, choose one of the datasheets on this page:
http://www.alsc.com/products/sync.htm

Cheers

PeteS