Invalid JTAG configuration - Invalid JTAG configuration Description Due to a problem in the Quartus® II software version 12.0 SP2 and earlier, you may see this error in SignalTap™ II Logic Analyzer when you use a USB-Blaster™ II cable with Arria® V devices. Resolution To work around this problem, perform the following steps after programming the SRAM Object File ( .sof ). Note that the jtagconfig executable can be found in <Quartus II software installation directory> /quartus/bin or <Quartus II software installation directory> /quartus/linux . Open a Command prompt Type the following command jtagconfig Verify which cable number you are using Type the following command: jtagconfig --setparam <cable number> JtagClock 16M Verify the change by typing the following command: jtagconfig - -getparam <cable number> JtagClock This issue has been fixed beginning with the Quartus II software version 12.1. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus II Software'] 12.1 12.0.2 ['Arria® V GT FPGA', 'Arria® V GX FPGA', 'Arria® V GZ FPGA', 'Arria® V ST FPGA', 'Arria® V SX FPGA'] ['novalue'] ['novalue'] ['novalue']