Don,
I'll take a stab at your question, though I'm basing this response on background information that a friend who designs ASICs was telling me. So I may have misunderstood, or I may not communicate it well, and I'd suggest you really wait for a true technical person to respond, but here goes:
The ASIC companies (LSI, TI, etc.) have all developed building blocks that you can drop right onto your custom chip design. Here's a page listing some of the building blocks from LSI's Coreware library (http://www.lsilogic.com/products/coreware/coreware.html#library). This building block approach saves chip designers from having to recreate all the wheels that have been previously invented. You can drop a D-RAC memory interface onto a chip with an ARM processor core, add the Ultra-ATA disk drive and PCI interfaces, and, voila, you have a computer on a chip.
I didn't check closely but I'd bet that Coreware also includes building blocks for SDRAM and maybe even other types of memory. You'd just drop the SDRAM building block onto your chip instead of the D-RAC. I don't know anything about Qualcomm, but if they're using LSI ASICs, then at least there's the possibility that they could use RDRAM, but it's probably also very possible that they could use SDRAM or other memory types.
I'm extrapolating this from conversations with this friend. I'll be curious to find out from the technical folks on the thread if I'm even close to correct.
And if I'm explaining something you already know, I apologize (and maybe you can correct any errors <G>).
Dave |
