[LPCXpresso804 board(OM40001)] on-board debugger issue: only can receive first byte.

Document created by Hao Liu Employee on Apr 14, 2019
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LPCXpresso804 board has a on-board debugger developed with LPC11U35. Old batches of the board uses the old firmware for LPC11U35 debugger.


The old firmware has some issues such as that when you send a string through the debug COM port the LPC804 only can receive the first byte.


The solution is easy. We can download the newest firmware for LPC11U35 and update the firmware for LPC11U35.


  • Download the fimware.

The firmware and driver can be download from this link.


  • Update the firmware.(Details can be found in UM11083: User Manual for LPCXpresso804 Board)
  1. Hold down the reset button and keep it held down while applying power to the board. Release reset. Using File Explorer (or equivalent on Mac/Linux platforms), look at the available drives on your system. A device called CRP_DISABLED will appear.
  2. Delete the firmware.bin file on the CRP_DISABLED drive.
  3. Drag and drop the firmware.bin file you downloaded from nxp.com on to the CRP_DISABLED drive.
  4. Re-power the board.
  5. The board should now enumerate on your system - allow 20-30 seconds for this to complete.