Keil MDK Holtek Edition

Arm provides software developers working with Holtek devices based on the Arm Cortex-M0+ processor with a free-to-use professional tool suite.

Download MDK

The free Keil MDK Holtek Edition – Cortex-M0+ edition includes the Arm C/C++ Compiler, the Keil RTX5 real-time operating system kernel, and the µVision IDE and debugger. If you wish to program also Holtek's Arm Cortex-M3 based devices, purchase the Keil MDK Holtek Edition – Cortex-M0+/M3/M4 online.

Serial number

Follow the installation steps described on the Getting Started page.

To activate one of the editions, you need a valid serial number:

  • Please enter your email address below to receive your individual serial number for the free Keil MDK Holtek Edition – Cortex-M0+.
  • To activate the Keil MDK Holtek Edition – Cortex-M0+/M3/M4, visit Arm's online store and buy the extended Holtek edition.

In both cases, you will receive a serial number that you can use in the activation step.

License generation

  • Go to Arm Developer - Support and select Licensing - Generate.

  • Log in into your already existing Arm account or create a new one.

  • Enter the serial number XXX:


  • In the next dialog, enter your host ID:

Note: Consult the FAQ to find the host ID of your computer.


  • Confirm that the entry is correct.

  • Press the Download button to retrieve the license from the server.

  • Press Download again to save the generated license.dat on your computer:


  • Make a note of the download location and press Close. This concludes the license generation.



  • Run µVision.

  • Open the dialog File — License Management..., select the FlexLM License tab, and click on Edit...:


  • Click the button Select File... and point to the file that you have received downloaded in the previous step:


  • If the license is correct, the Support Period will be presented and the output shows:

    *** FLEX Settings Modified Successfully ***

  • Click Close to finish the activation.