The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 21, 1998
Filed:
Jun. 13, 1996
Jonathan P Lotz, Fort Collins, CO (US);
Gregg B Lesartre, Fort Collins, CO (US);
Donald M Kipp, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A recovery method for each instruction in an instruction queue comprises steps of monitoring a launch bus to determine when an instruction has executed and comparing the tag number of the launched instruction with the tag numbers of the instructions upon which the instruction in the queue depends. After all dependencies for the instruction in the queue have cleared, a flag is set to indicate that the instruction is ready to launch. Even though all dependencies have cleared and the flag is set, the instruction in the queue still monitors the tag bus to check whether an instruction upon which it depends ever reexecutes. In the case that the instruction does reexecute, the instruction in the queue once again sets its flag to indicate that it is ready to launch, whereby the instruction in the queue will also reexecute. The recovery method permits the queue to operate at an optimal speed since each instruction need not wait until it is known for certain that its data will arrive before executing but rather may speculatively execute. Further, the recovery method does not require additional complex hardware but instead employs existing circuitry to monitor the reexecution of instructions.