TV80 core documentation needed

[madalin1990]

Good evening!
I have the verilog code of the tv80 core but i couldn't find any good documentation on it.So if someone has some good docs or know a place where to find it i would be very grateful.

Thank you in advance!

 

[ads_ee]

Is this what you're talking about a Z80 Verilog port?
https://sites.google.com/site/ghutchis/tv80homepage

According the the author the Z80 documentation and reference are what you are looking for.

 

[madalin1990]

Yes this is it. From what I understand tv80 si the VHDL Z80 microprocessor core written in Verilog.Am I right?

 

[ads_ee]

Yes, based on the information on the site I posted that is exactly what the author of TV80 did. Though he does state that his implementation isn't an exact copy of the Z80 design. I suppose there are some things that behave differently than the Z80.

 

[madalin1990]

Yes, I saw that TV80 has some additional pins.

 

[joelby]

I haven't looked at the TV80 specifically, but one common change when building a soft core based on a real device is to convert tristate I/O into separate input and output buses, because FPGAs tend not to have internal tristate logic.

 

[madalin1990]

I saw this difference too. But I didn't quite understand it. I have implememtented designs where I had inout ports and they worked perfectly.As an example you can look at Adept EPP.

 

[joelby]

Tristate I/O is supported on FPGA pins, just not in the internal fabric. With some synthesis tools you can use them internally, but as tristate logic is not actually implemented it will be emulated.

 

[madalin1990]

Good to know from now on.:-D