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:
May. 31, 1994
Filed:
Jan. 19, 1993
Russell Reininger, Austin, TX (US);
William B Ledbetter, Jr, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A sequential prefetch method is provided for a pipelined data processor having a sequential instruction prefetch unit (IPU). An instruction queue in the IPU is coupled to a pipelined instruction unit and an instruction cache of the data processor. A prefetch controller in the IPU keeps the instruction stream prefetched so that the instruction queue may load any combination of one, two, or three word instructions into the pipelined instruction unit every clock cycle. The pipelined instruction unit receives instruction words from the instruction queue, and decodes the instruction for execution operations, and for the instruction length/pipeline movement. A queue filling method is provided for maintaining the requisite number of instruction words in the instruction queue to avoid pipeline stalls. The queue filling method is based upon the movement of the instruction pipeline attributable to the usage by an instruction sequencer of the instruction words received from the instruction queue.