Multi-Step Flash Bootloader for Electronic Transmission Control Unit

An automotive supplier for electronic components develops and produces control units for automatic transmissions with torque converter. The scope for Helbling is to develop a three-step boot concept and implement it in separate software units.

  • Renesas microcontroller with separate CAN module

  • Three discrete boot levels, tailored to the requirements of the producers in the supply chain (producer of ECU, transmission and OEM)

  • Initialization and test of the microcontroller periphery

  • Compatibility and validity check of the subsequent boot level

  • Flash download of higher boot levels and drive program using UDS over CAN

  • Tester authentication and signature checking of downloaded software

  • Production test mode and processing of automated end-of-line tests


  • Consolidate and analyze requirements of different stakeholders

  • Establish three-step boot concept

  • Implement requirements in all boot levels

  • Test of the complete functionality at customer’s lab car

Results / Success

The Boot components are successfully developed and delivered to the customer. As part of the control unit software they are in series use.

Reference projects

Get in touch with us

Contact now