USB programmer for CPLD

[John_Correa]

Hi everyone,

I want to design a development board for CPLD. The existing board that I have right now uses the parallel port for programming the CPLD. Most of the computers these days dont have a parallel port these days. Hence I want to make the programming interface using USB.

Does anyone have a circuit diagram for programming the Xilinx/Altera CPLD's through USB? I dont want to use the readymade programmers available in the market as they cost a lot.

Please let me know if anyone has any leads.


Thanks and Regards,
John

 

[FvM]

You didn't tell, if you just want a generic JTAG programmer (there are plenty designs on the internet, you can use e.g. the JTAG library
from FTDI) or if you intend compatibility with manufacturer tools as Altera USB Blaster or respective Xilinx tools. You'll find extensive
discussions also regarding the latter at edaboard.

 

[srizbf]

as you say that present pcs have only usb and not parport.

my suggestion is a lowcost solution: in your case is buy an 'usb2lpt' adapter.

in this way you can use new pcs and your already tested cpld programmer.

no need to make a new usb cpld pgmmer.

srizbf
19thmay2010

 

[John_Correa]

@FvM: Any generic JTAG programmer which can burn the synthesized code onto the CPLD will suffice. I am not expecting any compatibility with the manufacturer tools available in the market.


@srizbf: Sir, are you sure that a 'usb2lpt' will work? If it does then I have no problems using it.


Thanks and Regards,
John

 

[srizbf]

the 'usb2lpt' adapter will definitely work when it is from reliable manufacturer.

srizbf
19thmay2010

 

[John_Correa]

Sir,

Could you please suggest a reliable source of the 'usb2lpt'?

Thanks and Regards,
John

 

[srizbf]

there are many in market without any name on the adapter.

if you get an adapter with a company name on it ,
then it can be used safely.
(many chinese noname origins are in markets)

get taiwanese/chinese (only available as for i know).
if you see the driver disk that comes with the adapter you may identify.

the noname adapter can also be bought provided the shop has a rapprt with you and exchange for another one if found not working .


i dont know which part of the world you are in.
and what windows version you use?

srizbf
19thmay2010

 

[John_Correa]

Sir,

I'll look for one of the cables you mentioned. But do I need to use some specific software for it or the one that works with the parallel port will identify the cable.

The current board that I have is using the Xilinx CPLD and it can be detected and programmed using iMPACT.


Thanks and Regards,
John

 

[srizbf]

you dont need any specific sw for this.
install the driver that comes with usb2lpt.

then you start using your original sw.
current software will continue to access the board.

srizbf
19thmay2010

 

[Guest]

The usb-to-parallel converters enumerate as a printer class device. I have several different cables.

The Xilinx XPC4 cable driver uses low level i/o routines to access the parallel port hardware. Using a usb-to-parallel converter will not work with the XPC4 cable.

You're better off buying a used Xilinx USB cable or clone off eBay.

 

[mrflibble]

What devnull said! Generally parport jtag cables use lowlevel bitbanging, which will not work with your typical (i.e cheap) usb-to-parallel adapters. Mind you, there are usb-to-parallel adapters that implement the full parport, but these cost on the order of $100. You are far better off getting a usb jtag cable.

Something seems affordable to me...

If you want to roll your own in a cheap & multipurpose way you could get a cheap coolrunner-II cpld board **broken link removed** with usb interface, and program that to do your jtagging for you.

 

[FvM]

the 'usb2lpt' adapter will definitely work when it is from reliable manufacturer

The statement is at least misleading in my opinion. Most usb2lpt adapters on the market are using one out of a small choice of available bridge ICs
from major manufacturers. At least some of them have a hardware option to emulate a legacy LPT port including bit-banging operations by special
USB commands. But if this mode isn't supported by the driver, it's void.

Please tell, if you know of a certain working USB adapter/LPT programmer combination, e.g. for Xilinx, Lattice or Altera. The topic has been previously
discussed at edaboard, but no contributor has yet reported a working example. My personal conclusion has been (up to now) that no manufacturer
did take the effort to write a reliable emulating driver. But I'm looking forward to be corrected in this regard.

 

[srizbf]

i have used an usb2lpt for another application.

the advice is based on my experience on usb2lpt adapters in the market.

as the adapter is going to be used for different purpose
i can suggest to get this adapter for that specific task.

please visit: **broken link removed**

hope this will solve the requirement.

srizbf
23rdmay2010

 

[eSilviu]

as you say that present pcs have only usb and not parport.
my suggestion is a lowcost solution: in your case is buy an 'usb2lpt' adapter.
srizbf
19thmay2010

JTAG burner will use parallel port at low level. It's the same problem from CNC area, where there are many software based on parport, but none will work with usb/parallel adaptor.

So: no, none of the ubs to parallel port will ever work. I will eat-it if it will work (usable, not 60min/burning a CPLD)

ft2232, if I remember correct, has JTAG interface, and is supported by OpenOCD
worth trying.