[Oberon] SRAM or SDRAM

[skulski at pas.rochester.edu]

Was: Re (2):  Spartan 6 Kickstarter project

Peter:

> Seems that 2 MiB FeRAM chips which connect as SRAM are now available.
> http://www.cypress.com/AsyncSRAMECC

These are sampling, but the final price is not known. Similar regular
(volatile) 16 Mbit Cypress chips CY62167EV30LL-45ZXI cost $13.6 at Digikey
(if you buy a hundred) or $10.2, if you buy a thousand. This is not cheap.
The FeRAM chips are likely to be more expensive. The SRAM technology is
simply not cost effective compared to SDRAM.

> Four of these connected to the FPGA based system
> can make an instant on machine?
> The file based boot process can be eliminated?

Hardly so, because you need to boot the FPGA. You can make an instant-on
machine if you use a hard processor, but not the FPGA. There are
instant-on FPGAs out there, like Spartan3AN, but they are rare. The
Spartan3AN is obsolete at this point. Not a good idea to use it.

Wojtek