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Case Study · Automotive

Motorcycle cluster.
Half the flash.
Same performance.

Renesas RH850 D1M1A Qt for MCUs Two-wheeler · Production

A leading global racing motorcycle manufacturer needed a new instrument cluster that matched the performance of its predecessor — but had to flash over CAN in under nine minutes. Crossware delivered both.

Motorcycle instrument cluster running Qt for MCUs on Renesas RH850
Platform
Renesas RH850 D1M1A
Technology
Qt for MCUs
Key result
30+ FPSCAN flash under 9 min
Industry
Automotive — Two-wheeler

Replace the cluster. Match the spec. Reduce the flash time.

The tier-one supplier needed to deliver a next-generation instrument cluster to a leading global racing motorcycle manufacturer. The requirement was clear: match the visual quality and performance of the outgoing cluster exactly — no regression on animations, responsiveness or feature set.

But a new constraint was added: the cluster firmware had to be flashable over CAN bus within nine minutes. The existing build was too large to meet this target. Reducing binary size without sacrificing what made the cluster good was the core engineering problem.

A visually rich cluster with no room to spare in flash.

The cluster was not a simple display. It had multiple layers of visual complexity that all contributed to binary size:

Startup animation sequence — a complex multi-frame visual sequence on boot that was stored as individual image assets, consuming a large portion of flash.
  • 01
    Complex RPM gauge animations

    The tachometer used high-fidelity animated sequences requiring significant image data. Frame count and image quality directly affected binary size.

  • 02
    Dynamic content strings

    Music playback, phone call information and turn-by-turn navigation all required dynamic text rendering and associated font assets.

  • 03
    Settings screen microanimations

    The settings UI had a dense layer of micro-interactions and transition animations — each contributing small amounts of asset data that accumulated significantly.

  • 04
    Full-screen images in settings

    Settings screens included full-screen background images — some of the heaviest assets in the entire binary, with limited scope for lossy compression under the original approach.

Two levers: hardware decode and delta compression.

Crossware approached the binary size problem from two angles simultaneously — exploiting hardware capabilities that were available but unused, and applying a smarter image encoding strategy.

  • 01
    Hardware JPEG decoder enablement

    The Renesas RH850 D1M1A has an on-chip JPEG decoder that was not being used. Crossware integrated and enabled this hardware decoder within the Qt for MCUs BSP, then converted the startup animation sequence from uncompressed image assets to JPEG. The result was a significant reduction in binary size for the most flash-intensive section of the firmware.

  • 02
    Delta frame technique for animation sequences

    Rather than storing each animation frame as a complete image, Crossware implemented a delta encoding approach — only the pixels that change between consecutive frames are stored. For animation sequences with large static regions (backgrounds, gauges), this eliminated the majority of redundant image data while preserving visual fidelity at runtime.

  • 03
    Full exploitation of all four RH850 D1M1A hardware layers

    The RH850 D1M1A provides four independent hardware rendering layers. Crossware restructured the UI composition to use all four layers — each handling a distinct visual plane of the cluster. This avoided software-compositing overhead and delivered consistent 30+ FPS across every screen, including the animation-heavy RPM gauge and the micro-animated settings screens.

One screen, taken apart. Each plane is rendered and stored independently, and the display controller composites them into the frame the rider sees — no software blend pass, no full-frame redraw when a single element changes.

LAYER 01Main ride viewDial art, tacho ramp & speed LAYER 02Bottom barStatus & function rail LAYER 03TelltalesSafety-critical indicators OUTPUTComposed frameHardware layer composition
Plane 01
Telltale layer

Indicators and warning lamps on their own plane. A telltale can illuminate or clear without the layer beneath it being touched.

Telltale layer in isolation — indicator and warning lamps along the top of the cluster, everything else black
+
Plane 02
Main layer

Speed, tacho ramp, gear and ride data. The animation-heavy plane, and the one carrying the delta-encoded frame sequences.

Main layer in isolation — tachometer ramp, gear indicator, speed and ride data, with the telltale strip and bottom bar absent
+
Plane 03
Bottom bar layer

The status and function rail. Because it sits on its own plane, a state change here costs nothing on the main layer above it.

Bottom bar layer in isolation — the status and function rail across the base of the cluster
=
Output
Composed frame

What reaches the display. Composition happens in hardware, which is what holds 30+ FPS through the animation-heavy states.

The fully composed cluster screen — telltales, main ride view and bottom bar together

Flash time target met. Performance maintained across all screens.

The combination of hardware JPEG decoding and delta frame encoding brought the firmware binary below the size required for nine-minute CAN flashing. No visual quality was sacrificed — the startup sequence, RPM animations and settings screens all rendered identically to the outgoing cluster.

< 9 min CAN flash time — target met
30+ FPS Sustained on all screens including animation-heavy states
4 layers All RH850 D1M1A hardware rendering layers utilised