thanks for sharing the link : very nice piece of hardware.
But i wonder : should it be posted inside zilog forum , are you having something to do with parallax ?
... just kidding if you other examplelike this , please post !

A response from zilog could be a Z80 or Z8 core + CPLD logic around ?

No, I have nothing to do with Parallax. I actually have a soft spot for Zilog as I learnt all about computers and electronics on Z80s way back in the late 1980's while doing my EE degree. Did some work on 6809s and 68000s before going into the telecoms industry. I have recently got back into micros as a hobby using Z8 Encore XP and AVR development kits.

My comments about Parallax were to demonstrate that the open-source community have been able to develop such a complex emulator using a cutting edge micro and do away with the need to use a real Z80 (or Z180) even though these are still available. You can see a photo of the actual board and a comment by the developer in an old hackaday article here:

hackaday.com/2009/12/27/zilog-in-a-matchbox/

AVR is progressing equally well. Just search for Arduino (an open-source AVR platform) on Google and see how many projects use it.

This is where the competition is at and Zilog needs to catch up.

Leo wrote:
thanks for sharing the link : very nice piece of hardware.
But i wonder : should it be posted inside zilog forum , are you having something to do with parallax ?
... just kidding if you other examplelike this , please post !

Leo,

I think that what the OP meant to say (and it's been partly confirmed by his answer) is that when your products can be simulated by another product that is supposed to be a direct competitor, something's smelly. I don't have the exact specs of that simulator or anything, it might be dreadfully slow, but it's a beginning. The Z80 seems to be slowly sliding into history.

At least that's how I read the post.

A response from zilog could be a Z80 or Z8 core + CPLD logic around ?

I though aboout that at some point. It's really convenient in a way, but introduces tons of problems, one of them being the tools used to program the CPLD, and the openness thereof. If the specs are complete and free for all, with a smart pin crossbar system, it might be very nice. But if it's locked down, well too bad. Zilog doesn't have the market power of Xilinx. No ecosystem, no sale.

And then, why should I design that part in instead of just using a small CPLD of FPGA?

i was reading some info about this platform it runs Z80 "faster than 4MHz equivalent" i believe it s decent speed for legacy softwares
but that attracting for nowadays standards.
...
CPLD does not need to be big , just to enable some more flexibility on peripherals .

At least that's how I read the post.

You read correctly.

So far, people have been emulating old microprocessors on the PC platform - all software. Now, I can emulate a Z80 plus peripherals on a competitor's micro that costs less, gives more functionality and is much smaller than the real thing. Sure, the emulator runs like a 4MHz part now but the next increment in clock speed will narrow the gap between the real part and the emulation. There's nothing stopping me from emulating other micros either as is already happening on this platform.

So, this goes back to my original point. For Zilog to become mainstream again (at least in the embedded space), they have to do good R&D and make something groundbreaking again (like the Z80 was in its time) as well as provide the environment to encourage the open-source community to get involved (as happened with the original Z80) otherwise the PICs and AVRs will dominate. I hope that the acquisition of Zilog by IXYS will provide the right environment to improve Zilog.

One great feature of the current Zilog MCUs (eZ8, ZNEO) that I like is the 1 pin in-circuit debugger interface. I haven't seen anything similar in any other MCUs from other manufacturers. Okay Microchips PIC uses 2-3 pins (i think), which is reasonable, but some ARM JTAG interfaces have like 20pins or more, which is insane.

Many "newbies" use AVRs for their first projects. The AVR doesn't have a "cheap" in circuit debugger. I think an in-circuit debugger is one of the most valuable tool for a beginner. Also all the ARM Cortex M3s that I've encountered don't have a "cheap" in-circuit debugger.

Zilog could focus more on features like that. Also opening-up the interface details would be a good thing.