Could not stop ARM device!


I am trying to load my code into a LPC2129 with ULINK2 and appears an error message saying: "Could not stop ARM device! Please check the JTAG cable". I tried to change the JTAG clock to 100 kHz and did not work. I tried with another ULINK2 but nothing changes.

How can I solve the problem?

Best regards,


  • So a relatively old ARM7 design. Your design? Some other vendor? Board of known functionality?

    The JTAG pins might be incorrect and not actually functional. All pins? JTDI, JTDO..

    Absent NRST/NRESET to actually control the core? Check NRST state, check supplies and BOR/POR thresholding devices on board, or on chip.

    Pins getting reconfigured, or powered down. Watch for low power modes, or disabling the interface, or clocking/settings of pins.

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