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:
Feb. 01, 1977
Filed:
Feb. 18, 1975
Edward C Hepworth, Apache Junction, AZ (US);
Rodney J Means, Tempe, AZ (US);
Charles I Peddle, Norristown, PA (US);
Motorola, Inc., Chicago, IL (US);
Abstract
An MOS (Metal-Oxide-Semiconductor) integrated circuit includes four dedicated registers thereon, two of which are 'write only' registers having the capability of being written into, but not read from, by means of buffer circuitry for coupling a bidirectional data bus to the dedicated registers. The other two dedicated registers are 'read only' registers having the capability of being read from, but not written into, by means of the buffer circuitry. The integrated circuit chip is itself addressable by means of a plurality of address conductors of an address bus coupleable to the integrated circuit chip, and the four dedicated registers within the integrated circuit chip are further addressable by means of an additional address conductor called a register select address line. A control input conductor is coupled to the integrated circuit chip and is used to control the direction of data flow of the buffer circuitry and is also used in conjunction with the register select address line to select one of four dedicated registers. This provides the advantage of reducing the number of external connections required for the integrated circuit chip, and is possible only because the registers are dedicated.