MB86290A 'CREMSON'
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 Block diagram - click to enlarge |
 With Fujitsu graphics processors graphical information can be displayed on four overlapping independent layers Click to enlarge image |
MB86290A 'Cremson' is a 2D/3D graphics controller optimised for applications in car navigation systems and mobile information processing terminals. Adopting various sophisticated functions, such as flat or Gouraud shading, bi-linear texture mapping, and Z-buffering, Cremson delivers high-speed and superior-performance 3D graphics functionality.
Moreover, anti-aliasing, concaved polygon rendering and fast line draw features are also included, allowing smooth and sophisticated-quality rendering. As a result, Cremson performs high-quality rendering operations, with similar quality to leading-edge PC graphics, but with lower power dissipation. Cremson supports a 64 bit wide external memory interface. This interface is driven at the same 100MHz frequency as its internal operation to support the large-memory bus bandwidth that is needed to perform the high-performance graphics operations described above. Also, in order to support various kinds of system configurations, Cremson offers a configurable host interface for four types of CPUs (Fujitsu FR30, Hitachi SH3/4 and NEC V832) without external glue logic.
To address the especially complex window configurations of car navigation systems, Cremson offers 4 layers of overlay planes. These layers are (from top to bottom): C (console) layer, W (window) layer, M (middle) layer and B (base) layer. All layers can be rendered in 16 bit/pixel colour (65,536 colours displayed at a time) or rendered in 8 bit indirect colour mode (256 selected out of 262,144 colours). The colour palette can be defined separately to the C-layer and B and M layers. A transparent colour option is used to blend the layers directly.
For screen separation in wide-screen displays, the M and B layers can be split into two separate segments (left and right). This feature is useful when two different reduced map scales are displayed side by side. Of course, all these layers and segments can be scrolled independently. Two hardware cursors are supported in addition.
An 'alpha-flag' per pixel is supported for the C-layer. This feature is useful for blending the C-layer colour with all the layer contents above, providing a variable transparent colour effect ('alpha-blending').
Cremson consists of 4 block modules: host interface block, external memory interface block, display control block and 2D/3D rendering block. These modules are connected by an internal 64 bit bus called 'Pixel Bus'. Also, the host interface block is connected to each of the other 3 blocks independently to avoid display and/or rendering operations when the host CPU attempts to access these modules.
Key Features
- CMOS 0.25µm technology
- Display resolutions up to 1024x768
- 4 layers of overlay display (bottom 2 layers are both split into separate segments)
- RGB analogue output (high speed DAC)
- Includes various kinds of 2D/3D graphic acceleration functions
- Built-in alpha blending, anti-aliasing and chroma-keying
- Up to 32MB external graphic memory (SDRAM) 64 bit wide @ 100MHz
- Configurable CPU-interface for FR30, SH3, SH4, V83x CPUs
- Supply voltage 3.3V (I/O), 2.5V (Internal)
- QFP-240 Package
- Temperature range -40 to +85?C
