| Subject: RE: aranym <-> ACP: speed, value for money, |
Author: Johan Klockars (as28-3-8.va.g.bonet.se)
Date: 12-03-2002 23:27
> Sure, a clone of the 68k could be written in a FPGA.
While it could be done, it would be a bad idea. The 68k is badly suited for FPGA implementation.
> I guess about 500MHz is max on the sort of FPGA we're talking about.
It's actually difficult to do _anything_ in even the fastest FPGAs at such speeds. There's absolutely no chance of a useful FPGA CPU running that fast any time soon.
100-200 MHz is possible for a reasonable pipelined RISC processor, though. The lower end of that is even doable in a decently priced one (Xilinx SpartanII - devkits start at $100-150 or so).
(Yes, I'm working on just such a CPU in that chip myself. ;-)
Take a look at www.fpgacpu.org for more information about CPUs in FPGAs. There's also a bunch of them at www.opencores.org.
> Might be quite expensive, certainly more than the Coldfire (about $25/euros).
The large FPGAs are very expensive indeed (as in several thousand dollars). They use huge chips (much larger than normal CPUs), though, and don't have very large markets, so it's certainly understandable.
Xilinx currently largest FPGA needs 42 Mbit configuration data. Since the configuration is stored statically, you can get a pretty good idea about the number of transistors that alone must take.
The chip in question has more than a megabyte RAM, 500+ 18x18 multipliers, 100k+ logic cells and 4 PowerPC405 processors (300+ MHz, 16/16 kbyte cache each). The smallest package has more than 1000 pins free for use.
Kind of impressive. ;-)
But, even Xilinx own optimized FPGA RISC processor (MicroBlaze) only reaches 150 MHz (102 Dhrystone MIPS) in that chip...
You could put a lot of them in there, though, since they only use 900 logic cells each. ;-)
> I think a 500Mhz optimised 68k in FPGA would be pretty powerful.
Any 500 MHz 68k would obviously be pretty powerful (relatively speaking). It will be years before it's anywhere near possible in an FPGA, though.
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| Topics |
Author |
Date |
 aranym <-> ACP: speed, value for money, futu new |
replicant |
12-03-2002 01:09 |
 RE: aranym <-> ACP: speed, value for money, new |
The Paranoid |
12-03-2002 10:58 |
 RE: aranym <-> ACP: speed, value for money, new |
GokMasE |
12-03-2002 12:31 |
| RE: aranym <-> ACP: speed, value for money, new |
replicant |
12-03-2002 13:50 |
 RE: aranym <-> ACP: speed, value for money, new |
Alex F. |
12-03-2002 16:04 |
 RE: daydreaming new |
replicant |
12-03-2002 16:33 |
 RE: daydreaming new |
Mr. B.B.C. |
12-03-2002 22:38 |
| Aranym such slow? new |
Alex F. |
12-03-2002 15:49 |
| RE: acp value for money? new |
replicant |
12-03-2002 16:43 |
| RE: acp value for money? new |
Johan Klockars |
12-03-2002 17:43 |
| RE: aranym <-> ACP: speed, value for money, new |
replicant |
12-03-2002 13:35 |
| RE: aranym <-> ACP: speed, value for money, new |
Mr. B.B.C. |
12-03-2002 22:30 |
| RE: aranym <-> ACP: speed, value for money, new |
The Paranoid |
12-04-2002 09:28 |
| RE: aranym <-> ACP: speed, value for money, new |
Lyndon Amsdon |
12-03-2002 22:14 |
| RE: aranym <-> ACP: speed, value for money, |
Johan Klockars |
12-03-2002 23:27 |
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