Invention Grant
- Patent Title: Method and apparatus for clearing hazards using jump instructions
- Patent Title (中): 使用跳转指示清除危害的方法和装置
-
Application No.: US11284069Application Date: 2005-11-21
-
Publication No.: US08171262B2Publication Date: 2012-05-01
- Inventor: Niels Gram Jeppesen , G. Michael Uhler
- Applicant: Niels Gram Jeppesen , G. Michael Uhler
- Applicant Address: US CA Sunnyvale
- Assignee: MIPS Technology, Inc.
- Current Assignee: MIPS Technology, Inc.
- Current Assignee Address: US CA Sunnyvale
- Agency: Sterne, Kessler, Goldstein & Fox, P.L.L.C.
- Main IPC: G06F9/30
- IPC: G06F9/30 ; G06F9/40 ; G06F15/00

Abstract:
A method and apparatus for overlaying hazard clearing with a jump instruction within a pipeline microprocessor is described. The apparatus includes hazard logic to detect when a jump instruction specifies that hazards are to be cleared as part of a jump operation. If hazards are to be cleared, the hazard logic disables branch prediction for the jump instruction, thereby causing the jump instruction to proceed down the pipeline until it is finally resolved, and flushing the pipeline behind the jump instruction. Disabling of branch prediction for the jump instruction effectively clears all execution and/or instruction hazards that preceded the jump instruction. Alternatively, hazard logic causes issue control logic to stall the jump instruction for n-cycles until all hazards are cleared. State tracking logic may be provided to determine whether any instructions are executing in the pipeline that create hazards. If so, hazard logic performs normally. If not, state tracking logic disables the effect of the hazard logic.
Public/Granted literature
- US20060101255A1 Method and apparatus for clearing hazards using jump instructions Public/Granted day:2006-05-11
Information query