| 摘要 |
PROBLEM TO BE SOLVED: To improve access efficiency to a main memory by limiting access to an outside main memory in a microprocessor having a cache memory. SOLUTION: This information processor is provided with instruction fetch parts 410 and 411 for fetching both instruction systems at the sequential side and target side of a branch instruction, cache controlling parts 54 and 56 for fetching instructions from a cache memory 52 or a main memory 64 in response to a fetch request from the instruction fetch part, a memory bus access part 60 for performing access to a main memory, and instruction buffers 470 and 471 for holding the fetched instructions. Moreover, this information processor is provided with branch predicting parts 430 and 431 for operating the branch prediction of the branch instruction stored in the instruction buffer prior to the execution of the branch instruction. When the branch direction of the branch instruction is uncertain, the cache controlling parts 54 and 56 control the memory bus access to the main memory 52 after cache miss.
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