Answers Database

EZTAG: Causes of Program and Erase problems


Record #1082

Product Family:  Hardware

Product Line:  Other

Problem Title:
EZTAG:  Causes of Program and Erase problems


Problem Description:
Below is a checklist of possible causes of problems with programming
and erasing 9500 devices with the EZTAG cable.


Solution 1:

1.  Check the JTAG connections.
     -TCK should be connected to system TCK
     -TDI should be connected to system TDI
     -TDO should be connected to system TDO
     -TMS should be connected to system TMS

2.  Vcc and GND must be connected to the cable.

3.  Parallel port problems.
    Certain implementations of the parallel port are not
    correctly backward compatible with the old PC AT
    "standard."  A few that we have seen to exhibit the
    problem are Gateways, Compaqs, and with SMC or Winbond
    parallel port drivers.

    The fix in this case is to try another PC, or go out and
    buy an inexpensive parallel port card.  These simpler
    parallel port cards tend to be the AT types that work
    best for the programmer.

4.  If there are parts in the programming chain that are not
    xc9500 parts, the problem may be due to a bug in the
    software.

    Download the patch from the FTP site, called EZTAG_PC.ZIP
 (Xilinx File ftp://ftp.xilinx.com/pub/swhelp/cpld/eztag_pc.zip)

5.  If the problem is with erasing, and suggestions 1-4 do
    not help, repeat the erase 8 times.  If the device
    suddenly erases successfully, then try to program and
    verify it.	If this works, the part is okay.

    If it still won't program or erase, it may be a
    defective part.



End of Record #1082