Date: Thu, 2 Jan 2014 10:28:22 -0700
From: Eric Smith <spacewar at gmail.com>
Reply-To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Subject: Re: RFC Ethernet Bus Interface V1
On Thu, Jan 2, 2014 at 7:18 AM, emanuel stiebler <emu at e-bbes.com> wrote:
If you compare what's inside of a zynq, and
compare to to a solution which
is made out of a external ARM + FPGA attached to it, please compare it to
an at least ARTIX-7 series,
Why compare to "at least Artix-7"? That artificially inflates the
comparison. Spartan-6 is far more cost effective than any 7-series. I
don't care what name the FPGA is marketed under; I only care how much logic
I can cram into it, and (to a lesser extent) how low the propagation delays
are.
and a dual core with a pretty decent amount of
peripherals.
I don't *need* dual core for anything, but certainly you can get it. Dual
core Cortex-A9 SoCs are quite inexpensive.
Then subtract the headaches of constructing a decent bus between the two,
and you probably know
why I think they are cheap.
Ooh, the headaches of running a few dozen traces, I hadn't thought of that.
I can design circuits in HDL all day while standing on my head, but I'm
shivering in terror at the thought of having to run a few dozen traces on a
PCB.
If you don't need the performance at all, you
probably get away with
much smaller FPGA & a cortex MCU, but it is getting very close in price.
No, the two-chip solution is significantly less expensive for comparable
performance, and FAR less expensive if you relax the requirements a bit
(single-core Cortex A5 or A8, or ARM-9).
Eric
Thats been my conclusion as well (reluctantly because I would like a
integrated chip for our uses)
The Zynq is just way overpriced for what it is. Unless you need high processor
<=> FPGA bandwidth, a Spartan6 and a seperate Arm chip with simple bus
interface is 1/2 the price or less.
Peter Wallace
Mesa Electronics