| 摘要 |
A multiple-word virtual address flexibly expands the virtual address space of a computer system without requiring the modification of the word size of the computer system. In a memory system having a virtual memory mapped to an absolute memory, the virtual memory is divided up into multiple levels each having a plurality of memory banks. Each memory bank has a plurality of words. The multiple-word virtual address provides a plurality of words for specifying the virtual memory level, memory bank, and offset word within the memory bank, to describe a selected memory location. Special instructions are added to the instruction set architecture to set up a window of program visibility, called a peephole, into a selected area of the expanded virtual memory. Existing programs are compatible with the multiple-word addressing scheme, and can also reference virtual memory through a defined peephole. New programs using multiple-word virtual addresses can still call procedures requiring single word virtual addresses. |
