When configuring a device in JTAG mode through the Parallel Cable III, why does it fail on 10.1.03i IMPACT software?
When configuring a device in JTAG mode through the Parallel Cable III, why does it fail on some PCs?
The timing for Parallel Cable III is controlled by iMPACT configuration software. iMPACT drives the PC III TCK signal at 200-210 kHz and provides approximately 1.2 us of setup time on the TDI and TMS signals.
Because all of the signals on the PC III cable are controlled directly through the software via the PC III driver, the timing is somewhat dependent on the clock speed of the computer running the Xilinx configuration software.
These numbers were measured using a Dell Latitude laptop with an 850 MHz Pentium-III processor.
If you are using a faster PC, you may see issues with configuration over these cables. To work around this issue, use an SVF/XSVF file generated in iMPACT to configure via JTAG mode.
These files are played at a slower rate and will make the cable less susceptible to timing issues.
For more information on the Parallel Cable III - How much setup time does the Parallel Cable III provide on TMS and TDI? What is the TCK frequency for this cable? - Please see (Xilinx Answer 9803).