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Re: Speculation on ARM licensed by DRAM companies


I ran accross this today in the Arm microprocessor group, thought it 
maybe of interest.

Wayne.



torbenm@diku.dk (Torben AEgidius Mogensen) wrote:
>With Hyundai as the newest licensee of ARM, there are now a number of
>the largest DRAM manufacturers that have licensed ARM cores. This
>leads me to speculate on whether we in the future will see DRAM with
>integrated ARM cores. About a year ago I read a paper (I think it was
>in Computer Architecture News and entitled "Breaking the Memory Wall"
>or something similar) that speculated that it may be a good idea to
>put a simple RISC core on a DRAM chip. The arguments were:
>
>DRAM technology is typically as dense (or moreso) than typical CPU
>technology, the difference being mainly that fewer layers are
>available. But a suitably simple RISC design can be build to run
>reasonably fast even with this limitation. The authors (being from
>Sun) suggested a simplified Sparc core, but ARM seems like an obvious
>possibility. When the CPU is on the same chip as the DRAM, a lot of
>the time (and power) required to drive the signals across a bus is
>avoided, so you can get far lower latencies than with similar DRAM
>technology on separate chips. The line buffers in the DRAM can easily
>be modified to work as cache for the CPU. With 128Mb and 256Mb DRAM
>coming shortly, this would be enough for small systems, e.g. NCs, PDAs
>or game consoles. Even with smaller DRAMS, it would be ideal for
>embedded systems.
>
>This type of applications is exactly what ARM is mostly used for, so
>it seems like an obvious development. However, it would require a
>redesign of the ARM core to DRAM technology, something which the
>present licenses (AFAIK) do not cover. A license similar to the one
>DEC got to develop StrongARM would fit the bill, though.
>
>	Torben Mogensen (torbenm@diku.dk)
>
>P.S.
>Of the 10 posting that were in this group when I read it today, 9 were
>spams or replies to spam. Maybe it is time to make the group moderated.