Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Masakatu Yokoyama

Koyo Katsura

Shigeru Matsuo

Jun Sato

Takashi Sone

A graphic processor which controls reading, writing and transfer of graphic data for a display memory that stores graphic data. The processor includes a first unit which stores first address information for addressing the display memory and first pixel address information which points a pixel position in a word specified by the first address information, a second unit which stores second address information for addressing the display memory and second pixel address information which points a pixel position in a word specified by the second address information, a third unit which shifts graphic data of multiple pixels included in two consecutive words to extract continuous 1-word graphic data, and a fourth unit which implements drawing computations pixel-wise concurrently for one word depending on the number of pixels included in a word. Even if transfer source graphic data lies across two consecutive words, the processor fetches the source data in single reading, processes the data word-wise at once, and stores the result in the display memory.

Graphic data processing system

Graphic processor suitable for graphic data transfer and conversion

A graphic processor which controls reading, writing and transfer of graphic data for a display memory that stores graphic data. The processor includes a first unit which stores first address information for addressing the display memory and first pixel address information which points a pixel position in a word specified by the first address information, a second unit which stores second address information for addressing the display memory and second pixel address information which points a pixel position in a word specified by the second address information, a third unit which shifts graphic data of multiple pixels included in two consecutive words to extract continuous 1-word graphic data, and a fourth unit which implements drawing computations pixel-wise concurrently for one word depending on the number of pixels included in a word. Even if transfer source graphic data lies across two consecutive words, the processor fetches the source data in a single reading, processes the data word-wise at once, and stores the result in the display memory.

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Hitachi, Japan

Masakatu Yokoyama