Parallel JTAG cable on a USB-only W2K laptop?

:( you are right about eveything. sorry for you. iMpact uses kernel mode driver to talk to parallel port so even if you install kernel mode driver to emulate LPT at real io address this would not be recognized by iMpact, as it also uses kernel access and bypasses io virtualization.

what you can do:

1) there is a japanese project (visual studio project) for downloading xilinx FPGAs using FT232 or FT245 chips, basically you just connect FGPA to FT232 (1:1 pin map) and use the supplied downloader to download bitstreams.

2) you take free sources of Alter JAM player, and change the port access to work with the IO as described above [1]. then you have JAM player that works with USB JTAG cable.

unfortunatly the JAM files produced by iMpact do have sometimes trouble with unpatched JAM player, but this can eventually be solved.

above link has the info about using FT232BM/245BM I was going to offer you a free usb module but it has FT232AM on it and cat be used. sorry.

optionally, if you need low low cost there is a free design

the above can be built from components of total cost aroung 5 USD and it works, could also be used for downloader (but would be REAL REAL SLOW!!)

antti

Thank you for confirming my suspicion that I cannot accomplish this task with a USB adapter. I have ordered a Quatech SPP-100 PCMCIA to Parallel adapter. I believe it will install as an LPT device properly and do the job. Thank you again. Carl

I have a feeling you might be pushing it .. but I'd like to hear the outcome.. The parallel port is treated as a bit bashed I/O port by the downloader's where as the USB to parallel port is a printer port.. or an EPP port..

Xilinx do a USB to FPGA downloader box for about US$500.. that would be my best thought.. or there's a few USB - JTAG boxes that might also work. Altera have a similar device similar price..

I have often thought an EZ-USB would make a great FPGA downloader and at the same price as the parallel port downloader's.

Simon

A little early to announce but we have a simple USB/JTAG downloader. The downloader uses the FTDI245B chip + a SpartanII Xc2S50 for the TAP controller. The XC2S50 is first downloaded in bit-bang mode via the FTDI chip and then acts as a smart TAP controller. This is an open project with all design information (software, stiffware, schenmatics, gerbers) freely available.

The downloader supports 2.5V, 3.3V and 5V JTAG I/O and programmable clock rates up to 48 MHz. The programmer is USB powered (no adapter needed). Connector pinout is 26 pin superst of EJTAG pinout.

The current software allows downloading Xilinx Bit files and SVF files (Thanks Jim!) If you dont want to build it yourself, The programmer hardware is available from my company for $99.00

Peter Wallace

You made the right choice, I have one of these for my laptop and it works perfectly. By all accounts UCB->parallel converters just won't work with iMPACT.

Regards,

John

Now this sounds like a plan.. I would be interested in more info.. as would a few around here..

Sim>

Here is a link to the programmer

(at the bottom)

The support software link is to a zipped file of schematics and current software/stiffware...

Peter Wallace

I looked at that chip for a newer design but it draws so much power that it looks troublesome to stay under the 500 mA limit, at least for a simple low cost card with linear regulators.

I've got a low cost USBScope (2 channels ~30 MHz (100 Ms/S)) design using the FTDI245 and a XC2S100E as well, I would have liked to have used the Cypress part there but there is no hope even with switching regulators of staying below 500 mA with Cypress.

Peter Wallace