13 Nov
2011
13 Nov
'11
3:22 p.m.
On 11/13/2011 3:53 PM, Eric Smith wrote:
ben wrote:
Why do you all assume, it has to be on the FPGA. 512KB memory
not on the FPGA. Quickly looking at Digikey Canada -- Altera Flex 6000
seems
to fit my needs, but no development board. The DE0 board for now looks to
be a valid base development board for now. Looks like I'll order it
early next year.
Ben.
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.