How to connect the FPGA to a PC without using a JTAG cable?

[guzhal]

I have the usb cable to download the bitstream to the fpga. I have used the serial connector of my board to connect to the pc.
I don't have a jtag cable to connect my fpga(spartan) to the pc.But i found some softwares which emulate the behavior of jtag.I don't know how to use it also.
Is it possible to emulate the usb cable to behave as an JTAG cable...
pls. tell me whether it is possible to connect the FPGA to pc without using a JTAG cable..If possible how to do it..

 

[supercst]

help in fpga

The usb is not a JTAG download cable?

 

[rasj12]

Re: help in fpga

No, JTAG is differet from USB.
JTAG(Joint Test Action Group) is connected from Parallal port of PC to FPGA.
While USB is Universal Serial Bus!

 

[echo47]

help in fpga

JTAG is the best way to go.

Another possible method is to build a simple PC interface that talks to the FPGA's serial bitstream signals (such as Xilinx CCLK DIN PROG_B INIT_B DONE). However, most people don't do that because it restricts you to a specific group of FPGAs.

You can buy a USB-to-JTAG converter. It's a common way to add JTAG to a computer. Here are two examples:
**broken link removed**
http://www.digilentinc.com/Products/Detail.cfm?Prod=JTAG-USB

Or buy a Parallel-to-JTAG converter, if your computer has a parallel printer port. Two examples:
**broken link removed**
http://www.digilentinc.com/Products/Catalog.cfm?Nav1=Products&Nav2=Cables&Cat=Cable (scroll down to JTAG3)

Some folks build their own Parallel-to-JTAG converter. It's pretty easy to clone the old Xilinx Parallel Cable III. Here's a schematic:
**broken link removed**