Patent
1997-06-30
1998-10-06
Kim, Kenneth S.
395386, 395388, 395389, 395391, G06F 930
Patent
active
058190570
ABSTRACT:
A high performance superscalar microprocessor including an instruction alignment unit is provided which is capable of routing variable byte length instructions simultaneously to a plurality of decode units which form fixed issue positions within the superscalar microprocessor. The instruction alignment unit may be implemented with a relatively small number of cascaded levels of logic gates, thus accommodating very high frequencies of operation. In one embodiment, the superscalar microprocessor includes an instruction cache for storing a plurality of variable byte-length instructions and a predecode unit for generating predecode tags which identify the location of the start byte of each variable byte-length instruction. An instruction alignment unit is configured to channel a plurality of the variable byte-length instructions simultaneously to predetermined issue positions depending upon the locations of their corresponding start bytes in a cache line. The issue position or positions to which an instruction may be dispatched is limited depending upon the position of the instruction's start byte within a line. By limiting the number of issue positions to which a given instruction within a line may be dispatched, the number of cascaded levels of logic required to implement the instruction alignment unit may be advantageously reduced.
REFERENCES:
patent: 4044338 (1977-08-01), Wolf
patent: 4453212 (1984-06-01), Gaither et al.
patent: 4807115 (1989-02-01), Torng
patent: 4858105 (1989-08-01), Kuriyama et al.
patent: 5226126 (1993-07-01), McFarland et al.
patent: 5226130 (1993-07-01), Favor et al.
patent: 5371864 (1994-12-01), Chuang
patent: 5450605 (1995-09-01), Grochowski et al.
patent: 5488710 (1996-01-01), Sato et al.
patent: 5537629 (1996-07-01), Brown et al.
patent: 5586277 (1996-12-01), Brown et al.
patent: 5600806 (1997-02-01), Brown et al.
Intel, "Chapter 2: Microprocessor Architecture Overview," pp. 2-1 through 2-4.
Michael Slater, "AMD's K5 Designed to Outrun Pentium," Microprocessor Report, vol. 8, No. 14, Oct. 24, 1994, 7 pages.
Sebastian Rupley and John Clyman, "P6: The Next Step?," PC Magazine, Sep. 12, 1995, 16 pages.
Tom R. Halfhill, "AMD K6 Takes On Intel P6," BYTE, Jan. 1996, 4 pages.
Tran Thang
Witt David B.
Advanced Micro Devices , Inc.
Kim Kenneth S.
Kivlin B. Noel
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