A typical microcontroller for graphical instrumentation applications may feature a high-performance 2D graphics engine with Timing Control (TCON). Toshiba’s Capricorn-Bt1 has a two-output Graphic Display Controller (GDC) with TCON support, while the Capricorn-Bt0 provides a lower-cost option featuring a single-output GDC. The graphics engine at the heart of each device has 2.5D capability with support for warping, blitting with alpha merge, rotation, scaling, drawing and special effects like perspective transformation (figure 3). The ability to support graphics with depth information, using perspective transformation, enables smartphone-like features such as 3D cover flows with mirroring effects.
Figure 3. 2.5D graphics support with perspective transformation enables clearer visual communication and supports features like 3D cover flows.
To help trim bill-of-materials costs, Capricorn-Bt0/1 implement a PNG engine, keeping the demand for memory to a minimum. The GDC and Graphics Accelerator (GA) can read data in PNG format natively either from internal or external memory such as connected Flash-ROM or RAM. This allows the system to decompress PNG images on the fly and display these directly as a background layer without requiring intermediate storage. In addition to reducing demand for local storage space, this also frees up memory bandwidth for the whole image processing path.
Capricorn-Bt0/1 provides the unique MagicSquare™ dithering unit which performs spatial and time-based dithering for enhanced colour depth. This supports the option to connect a low-cost display with, for example, 18-bit colour resolution, and achieve close to 24-bit colour. This MagicSquare function has demonstrated a significant improvement in visual performance during tests with major automotive OEM brands, enabling crisp, clear graphics with improved contrast.
A dual-display interface is an increasingly common requirement in modern automotive instrumentation. This is to drive the display in the main instrument panel and another display, which may be mounted in addition in the instrument cluster or alternatively may be used to provide graphical information to a Head-Up Display (HUD). This feature is permeating some