The Z80 core is about three times the size of the 650x core and really can't
do anything the 650x core can't do quite a bit faster. If you clock the two
cores at the same rate, the smaller core is perhaps 5x as fast. It's small
because it's simple, having fewer resources. For a dedicated task, however,
the small controller's the better choice because it holds down the
requirement for resources.
Gate arrays are not relevant to the typical microcontroller application.
The gate arrays are handy when an MCU is not fast enough, but for short
runs, where the MCU's shine, the FPGA's and CPLD's are much slower to
develop.
The single-chip examples I think about when I'm considering what to use are
frequently the Scenix SX family. They're as fast as a core in an FPGA, and,
in fact, probably faster, and they cost a LOT less. Of course you have to
be able to make the tasks fit, but at the 10 MIPS rate, if you can partition
the task, perhaps pipelining two or more of the devices, they still can get
the job done VERY fast, yet at a fraction of the cost of a dedicated logic
device. Moreover, if you can design with pipelining and manage to devise a
scheme wherein multiple devices can make the job happen, it's still MUCH
less work than an FPGA.
Dick
----- Original Message -----
From: ajp166 <ajp166_at_bellatlantic.net>
To: <classiccmp_at_classiccmp.org>
Sent: Thursday, November 02, 2000 8:01 PM
Subject: Re: Monitor for iSBC 8024
> From: Richard Erlacher <richard_at_idcomm.com>
>
>
> >What I like about "single-chippers" is that you have the option of
> looking
> >at them as programmable logic. They're not all as fast as CPLD's, but
> >they're generally not as costly as a CPLD or FPGA capable of duplicating
> >their function. A Z80 CPU or one of its scions compatible with its
> >instruction set would still require external hardware to provide the
> >interface to read-write memory, then the memory itself, and the decoding
> for
>
>
> When I say "core" for a gate array I mean one of those large ones that
> can also provide the needed ram, rom and IO. As in ASIC.
>
> I almost did a job where the cpu core was 80C88, really hate that CPU
> and am glad I didn't.
>
> Allison
>
>
Received on Thu Nov 02 2000 - 23:07:39 GMT