Since, loading new bits files does not happen that often for me even when prototyping, the speed issue is not a big deal. However, I use JTAG only for programming. If you dig through his web-page, he mentions this fact and gives some numbers.

If I cannot make any headway, I will probably buy a USB2LPT and hope I do not run into the WIN XP issue. I will probably keep trying for the remainder of the week on the MOSCHIP device. Unfortunately, the WIN2K box does not have the IMPACT software installed, so I cannot test JTAG yet. However, on a Win2K desktop, I did get it to install and pass the internal loopback test. Two XP desktops install the device, but its own internal loopback test fails. My laptop will not run the device at all.

With regard to the MOSCHIP device, I do not seem to have gotten a good install on several XP boxes. If I can get an LPT port working via USB, I can support these programmers from my laptop as well. Also, I have several programmers for microcontrollers that only run from an LPT port. I may need to outfit a couple of laptops, so any price differential adds up quick. The Xilinx solution is a possibility, but the prices I was quoted are huge. (Should you wish to do that, please email the author as he wants to issue serial numbers for the EEPROM.) He would rather I would clone my own device(s) from his info on the web. He is probably selling these at close to cost. Considering the costs involved in hand building small quantities, his price is very low. Secondly, he is building these devices by hand and therefore availability is low. First, I am running XP and some XP machines have problems with his drivers. There are a couple of issues with his device. First, let me say that I have the utmost regard for his work. I have contacted the designer of USB2LPT. This device seems to be available on the web. (The port replicators that failed for me all say that scanners are not supported.) The manual for the device states that it will work with scanners that run in SPP mode. Has anyone gotten it to work for direct accesses to the LPT port for programmers like the Xilinx? If so, can you tell us the tricks? Can you report what version of driver you are using?Īgain, while this device shows promise, I have not gotten it to work yet. However, I am having lots of problems getting Windows XP to load the proper drivers.Ģ. From the datasheet for the chip, it seems fully capable of being used as a bi-directional port. I stumbled across one adapter that uses the MOSCHIP, MCS7705. I tried a couple of 'Port Replicators' but these use a chipset that does not allow any bi-directional operation. However, my laptop does not have a parallel port.

The simple circuit for connecting a parallel port to the Xilinx JTAG programmer is readily available on the web and works fine.

Xilinx jtag usb driver