SOFTWARE CONFIGURABLE MEMORY ARCHITECTURE FOR DATA PROCESSING SYSTEM HAVING GRAPHICS CAPABILITY

摘要

ABSTRACT OF THE INVENTIONA graphics data processing system memory isallocatable by software between system memory andgraphics framebuffer storage. The memory comprisestwo-port elements connected in parallel from the RAMport to a controller connected to a bus, and havingserial output ports connected to output circuitry tomap the storage to a display. Correspondinglocations, relative to element origin, in allelements are addressed in parallel as an array.Three modes of memory transactions are allaccomplished as array accesses. First, a processorreads/writes the system memory portion by acombination of parallel array access and transfersbetween controller and bus in successive bus cycles.Second, the controller executes atomic graphicsoperations on the framebuffer storage usingsuccessive array accesses; third, the processor canread/write a framebuffer pixel, by an array access offramebuffer storage with masking of unaddressedpixels. An interface arbitrates among requests formemory access.