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. 02, 1995
Filed:
Mar. 26, 1993
Robert J Skruhak, Austin, TX (US);
Michael E Gladden, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A data processor microsequencer having a non-multiplexed internal address bus is provided. The microsequencer includes a nanoROM, for providing control information to an execution unit, an entry point PLA for decoding a macroinstruction address and providing an initial microinstruction address, and a microROM, for providing the next microinstruction address during instruction sequencing. The entry PLA accesses macroinstructions from an instruction pipeline, and decodes the macroinstructions, thereby providing an initial microinstruction address for the microroutine to perform the macroinstruction. The initial microinstruction address is temporarily stored in a microprogram counter latch (uPC) and provided to the microROM or the nanoROM for decoding. The microROM decodes the initial microinstruction address and provides N output bits which are routed directly into the PLA, and subsequently provided to the uPC. The uPC selectively transfers the next microaddress to the microROM, and the microROM decodes the next microaddress, thereby providing subsequent microaddresses in the microroutine directly to the PLA. Strobe circuitry selectively activates either the microROM and the PLA, and in so doing, determines which unit provides the microaddress to the uPC.