Electrical computers and digital processing systems: processing – Processing control – Branching
Reexamination Certificate
2011-03-22
2011-03-22
Coleman, Eric (Department: 2183)
Electrical computers and digital processing systems: processing
Processing control
Branching
C712S238000
Reexamination Certificate
active
07913068
ABSTRACT:
A system and method for asynchronous dynamic millicode entry prediction in a processor are provided. The system includes a branch target buffer (BTB) to hold branch information. The branch information includes: a branch type indicating that the branch represents a millicode entry (mcentry) instruction targeting a millicode subroutine, and an instruction length code (ILC) associated with the mcentry instruction. The system also includes search logic to perform a method. The method includes locating a branch address in the BTB for the mcentry instruction targeting the millicode subroutine, and determining a return address to return from the millicode subroutine as a function of the an instruction address of the mcentry instruction and the ILC. The system further includes instruction fetch controls to fetch instructions of the millicode subroutine asynchronous to the search logic. The search logic may also operate asynchronous with respect to an instruction decode unit.
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Bonanno James J.
Prasky Brian R.
Rell, Jr. John G.
Saporito Anthony
Shum Chung-Lung Kevin
Campbell John
Cantor & Colburn LLP
Coleman Eric
International Business Machines - Corporation
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