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公开(公告)号:US5859992A
公开(公告)日:1999-01-12
申请号:US815566
申请日:1997-03-12
CPC分类号: G06F9/382 , G06F9/30152 , G06F9/3816 , G06F9/3836 , G06F9/384 , G06F9/3855 , G06F9/3857
摘要: An instruction alignment unit includes a byte queue configured to store instruction blocks. Each instruction block includes a fixed number of instruction bytes and identifies up to a maximum number of instructions within the fixed number of instruction bytes. Additionally, the instruction alignment unit is configured to form a pair of instruction lists: a dispatch list and a latch list. The dispatch list includes instruction locators corresponding to instructions within the instruction blocks stored in the byte queue. Additionally, the first three instructions from instructions blocks being received from the instruction cache during a particular clock cycle are appended to the dispatch list. The dispatch list is used to select instructions from the byte queue for dispatch to the decode units. The latch list is used for receiving instruction locators for the remaining instructions from the instruction blocks received from the instruction cache during the particular clock cycle. Furthermore, the latch list receives instruction locators from the dispatch list which correspond to instructions not selected for dispatch to the decode units. The latch list is stored until a succeeding clock cycle, in which the stored program-ordered list is used as a basis for forming the dispatch list during that succeeding clock cycle. The instruction identification information and instruction bytes corresponding to the instruction can be located by selecting the instructions corresponding to the instruction locators at the front of the dispatch list.
摘要翻译: 指令对准单元包括被配置为存储指令块的字节队列。 每个指令块包括固定数量的指令字节,并且在固定数目的指令字节内识别最多指令数。 此外,指令对准单元被配置为形成一对指令列表:调度列表和锁存列表。 调度列表包括对应于存储在字节队列中的指令块内的指令的指令定位符。 此外,在特定时钟周期期间从指令高速缓存接收到来自指令块的前三个指令被附加到调度列表。 调度列表用于从字节队列中选择用于调度到解码单元的指令。 锁存列表用于从特定时钟周期内从指令高速缓存接收到的指令块接收剩余指令的指令定位器。 此外,锁存列表从调度列表接收与未被选择用于发送到解码单元的指令对应的指令定位器。 存储锁存列表直到下一个时钟周期,其中存储的程序排序列表用作在该后续时钟周期期间形成分派列表的基础。 可以通过选择与调度列表前面的指令定位符相对应的指令来定位与该指令相对应的指令识别信息和指令字节。