United States Patent (19) 11 Patent Number: 4,486,827 Shima Et Al
United States Patent (19) 11 Patent Number: 4,486,827 Shima et al. (45. Date of Patent: Dec. 4, 1984 (54) MICROPROCESSORAPPARATUS (56) References Cited 75 Inventors: Masatoshi Shima, Santa Clara; U.S. PATENT DOCUMENTS Federico Faggin, Cupertino; Ralph K. 3.969,724 7/1976 And al. .................. 364/200 Ungermann, Los Aitos, all of Calif. sw-Y A lderson et w 73 Assignee: Zilog, Inc., Campbell, Calif. Primary Examiner-Felix D. Gruber Assistant Examiner-John G. Mills 21 Appl. No.: 340,470 Attorney, Agent, or Firm-Majestic, Gallagher, Parsons (22 Filed: Jan. 18, 1982 & Siebert Related U.S. Application Data (57) ABSTRACT 62) Division of ser. No. 092.827, Nov. 9, 1979, Pat No. A special reset function is provided in the CPU using 4,332,008, which is a division of ser. No.665228, Mar. the same control input to the CPU as the normal reset, 9, 1976, abandoned. to reset only the program counter to facilitate the use of 51 Int. C1.3 G06F 9/OO a single CPU in a microprocessor development system. 52 U.S. C. .................................................... 364/200 58) Field of Search ................................ 364/200,900 7 Claims, 14 Drawing Figures SEEgil A 0 0 - A ResET OSE CHP O cLRC f/f SPECA ReSeT data is preset our Ng cock is low, AA will se RANSFERREd to OPU on RSNG Ege of cock M 2 old RESETNORMA f d) NRES U.S. Patent Dec. 4, 1984 Sheet 1 of 13 4,486,827 8-BIT DATA BUS DATA BUS CONTROL INTERNAL DATA BUS INSTRUCTION DECODE 8 3 CPU CPU AND CONTROL CPU SYSTEM CPU REGISTERS CONTROL CONTROL SIGNALS O ADDRESS CONTROL 6-BT ADDRESS BUS CPUBLOCK DAGRAM FIG.
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