MB86290A Datasheet, PDF (43/184 Pages) Fujitsu Component Limited. – Graphics Controller Hardware Specifications

4.3 Memory Access
4.3.1 Memory Access by Host CPU
The Graphics Memory is mapped to the host CPU physical address field. The
host CPU can access the Graphics Memory of MB86290A like a typical
memory device.
4.3.2 Priority of Memory Access
The Graphics Memory accesses priority is as follows:
1. Refresh
2. Display
3. Host CPU Access
4. Drawing
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