Direct Mapping
Another, more popular way of organizing the cache is to use direct mapping. In a direct-mapped cache, each block frame can cache only a certain subset of the blocks in main memory.
Figure 11-6. Fully associative mapping
In Figure 11-7, each of the red blocks (blocks 0, 8, and 16) can be cached only in the red block frame (frame 0). Likewise, blocks 1, 9, and 17 can be cached only in frame 1, blocks 2, 10, and 18 can be cached only in frame 2, and so on. Hopefully, the pattern here is apparent: Each frame caches every eighth block of main memory. As a result, the potential number of locations for any one block is greatly narrowed, and ...
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