A higher graphics drawing performance is desired for the successful user interface in the present GUI(Graphics User Interface)-based Personal Computers which support high-resolution (above 1024*768) and high-color (above 256 colors) graphics modes. This paper proposes a graphics hardware accelerator architecture for higher drawing performance in the GUI environments, especially in the True Color graphics modes: GUIC48(A Graphics User Interface Controller which has a 48 bit interface to VRAM). To achieve higher bandwidth in the frame buffer interface, GUIC48 employs two bank VRAM frame buffer which can be accessed by paged interleaving with a 48 bit wide memory data bus. A 48 bit memory data bus boosts the screen-to-screen BitBlt(Bit Block Transfer) and the patterned quadrilateral drawing in the 24bpp(bits per pixel) graphics mode by approximately 2 times higher speed compared to the one which has a 32 bit interface.
The function of the proposed architecture is confirmed by hardware modeling in C programming language and test programs which test the drawing and the control functions. The graphics drawing performance of the proposed architecture is estimated by using the GUIC48 state diagrams. It's maximum drawing performance is expected to be, 94.2 MPixels/sec in the 256 color and 48.5 MPixels/sec in the 64K/16M color graphics mode for the quadrilateral drawing, and 42.4 MPixels/sec in the 256 color and 21.7 MPixels/sec in the 64K/16M color graphics mode for the BitBlt, regardless of the display resolution.