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:
Jun. 14, 1983
Filed:
Jun. 10, 1980
Hitachi, Ltd., Tokyo, JP;
Abstract
In a .phi..sub.2 cycle steal mode, a clock signal is selected such that a time period during which a RAM is connected to a timing signal generator for display is extended and a time period during which the RAM is connected to a CPU is shortened accordingly, without changing an overall period. This clock signal is used to actuate a switching circuit for the RAM while a clock signal having unmodified duty ratio is applied to the CPU, a ROM and external circuits so that a display data readout period from the RAM is extended without affecting the CPU clock frequency and the operation of other circuits. During this readout period, a plurality of display address signals are applied to the RAM from the timing signal generator and a plurality of data derived from the RAM are sequentially loaded in a register which is then read out at a desired timing to enable the display of a plurality of characters in one CPU clock period.