Quilted Dies of CPU & RAM was Re: [FoRK] Cheap Electronics Dissection Project

[Dave Long]

> Why not etch dies with either tiles of octagons and squares or just 
> hexagons?

Traditionally, DRAM-style memory (tricky cells, regular layout) and 
CPU-style logic (simple cells, irregular layout) use different 
manufacturing techniques and lines, so it's relatively easy to get them 
in the same chip but relatively difficult to get them on the same die.

It is possible to build entire systems with SRAM, but it's not usually 
cheap.  The old line about Crays is that after you bought the memory, 
they'd throw in some supercomputer CPUs for free.

But I get plenty of hits for "embedded DRAM", so maybe this is now a 
solved problem?

-Dave