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ChipScope Pro Software and Cores User Guide
UG029 (v14.3) October 16, 2012
Appendix A:
ChipScope Pro Tools Troubleshooting Guide
Table A-6:
Troubleshooting JTAG Device Detection Issues
Issue(s)
Solution(s) or Work-Around(s)
1.
On attempting to connect to the
cable you see one or more of the
following messages in the
console:
ERROR: No devices
detected while scanning the
JTAG chain
ERROR: Failed detecting
JTAG device chain
ERROR: Opened Xilinx
Platform USB Cable but
failed to detect JTAG Chain.
This is often due to JTAG chain
problem where TDI or TDO are
disconnected or pulled high or
low. This generally indicates
board-related issues.
Go to Issue #2.
2.
Are the Cable TDI and TDO
connected correctly at the cable
header?
If NO or NOT SURE: If possible, try using a different board, cable, or cable
connector to locate the fault. Modify connections so that you have a valid chain.
A different ribbon cable or fly leads for connection might help. Alternatively, a
different board might not have the issue.
If YES: Go to Issue #3.
3.
Is switching noise elsewhere on
the board causing the failure to
detect the JTAG chain?
If YES or NOT SURE: If possible, use a board-level reset to put other devices into
their reset state and try to detect the JTAG chain again. Asserting this reset might
reduce noise on the board during JTAG operations.
If NO: Go to Issue #4.
4.
Are non-Xilinx devices in the
JTAG chain?
If YES: Check to make sure that any active-low TRST# pins of these non-Xilinx
devices are pulled high, then try to detect the JTAG chain again.
If NO: Go to Issue #5.
5.
Is the active-low PROG# pin of
any Virtex®-4, Virtex, Virtex-E
or Spartan®-II/-E devices in the
JTAG chain being held low?
If YES: Make sure the PROG# pins of these devices are pulled high. A low pulse
on PROG# resets the JTAG TAP controller for these devices and prevent any
operation on the chain.
If NO: Go to Issue #6.