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. 17, 1994
Filed:
Jul. 03, 1991
David C Oliver, Maple Heights, OH (US);
John F Vesel, Willowick, OH (US);
Michael J Petrillo, Euclid, OH (US);
James M Kapcio, Cleveland, OH (US);
Picker International, Inc., Highland Hts., OH (US);
Abstract
A DMA control device (10) is connected with an n-bit address bus (12) by way of a bidirectional internal n-bit bus (14). The m most significant bits of signals received on the bidirectional bus (14) are reserved for carrying codes which identify or enable the DMA device to respond, to generate a load signal, to generate a count signal, and to generate an output signal. The remaining bits are reserved for address data. The load signal causes the remaining bit addresses to be loaded into counters (22) or registers (40). The count signal causes the counters (22) or a latched incrementor (44) to increment. The output signal controls three-state buffers (24, 42, 46) which cause the current address to be outputted on the bidirectional bus. In this manner, the DMA control device has only a single bus and in the embodiment of FIG. 2 replaces the counter array with a register array.