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Memory access failed / Scan IDCODE - No DAP device found on the JTAG chain

Question asked by Brett Stahlman on Dec 1, 2017
Latest reply on Jan 13, 2018 by Yiping Wang

When I attempt to connect to my LS1012A Reference Design Board for debugging, I get the following error:

Memory access failed.
Additional error details:
[Failed to write memory at address 0x1ee00e4 on core CortexA53#0.
Core CortexA53#0 not found on the JTAG chain. Please verify that the Reset Configuration Word is correct, or enable RCW Override in the initialization file.]

When I click the "Diagnose" button, I get the following error:

Scan IDCODE No DAP device found on the JTAG chain

The "More info" panel shows the following:

Detected IDCODE

TDO -----


   * Device 0  IDCODE: 4BA00477  Device: ARM DAP rev 4.x


TDI -----

No DAP device found on the JTAG chain


Please make sure the board DIP switches are correct regarding Debugger / Boundary scan mode as described in the README section.
If the board is fitted with multiple JTAG header connectors, please make sure the probe is connected to the correct one (usually labeled CPU JTAG)

I've looked at the README, and have tried both the "QSPI_BOOT" and the "Hard coded" switch settings. I've also set USE_SAFE_RCW = True. (Without this, I get an error even earlier.)


Is there something wrong with the IDCODE returned by my board? Any ideas on what could be causing the errors?



Brett S.