13 Nov
2011
13 Nov
'11
2:53 p.m.
ben wrote:
Remember this is the classic computer list so, being
about 10 years
behind is normal
around here. What can you recommend that has 5 volt
I/O,
The last Xilinx FPGAs with 5V-tolerant I/O were the Spartan 2 family.
They still make those, but they are tiny and slow by today's standards,
and you have to use a really old version of the Xilinx software to
develop for them.
I don't think the situation with Altera is any better.
Some of the latest FPGAs (e.g., Virtex 6) don't even have 3.3V-tolerant I/O.
I'm pretty much resigned to using external level shifters or
QuickSwitch-style parts when I need to interface to 5V systems.
nonvolatile memory and
Most FPGAs don't have nonvolatile memory. Certainly the mainstream ones
that have high logic density do not. They use a separate serial flash
part to load the configuration at power-up. (The Spartan 3AN includes
the serial flash part in the same package.)
mid-sized number of FPGA macro cells. Something one
can use to
emulate a PDP
computer with up to 512Kb of memory.
I'm not sure whether you mean 512 Kbits or KBytes. There are a number
of FPGAs with 512 Kbits of dedicated blockram, but if there are any with
512 KBytes, they must cost a fortune. You're generally much better off
with an external SRAM.