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:
Dec. 04, 1990
Filed:
Oct. 11, 1988
Hitachi, Ltd., Tokyo, JP;
Hitachi Microcomputer Engineering, Ltd., Tokyo, JP;
Abstract
A single-chip microcomputer has external terminals outputting a system clock signal, an address signal, and a data signals. External equipment such as an external memory is operated by address and signal which are output when the system clock signal changes. In the single-chip microcomputer of this invention, the operation of an address signal output circuit and that of a data signal output circuit are controlled by a signal output from a digital delay circuit which receives the system clock signal. According to this circuit construction, the hold time between the change in the system clock and the change in the address and data signals is determined by the delay circuit which exhibits a digital operation, so that the hold time can be set accurately without being affected adversely by any variation in the circuit elements due to the manufacturing process, or by temperature changes.