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, 1983
Filed:
Nov. 25, 1981
John M Dinwiddie, Jr, Loxahatchee, FL (US);
Bobby J Freeman, Boynton Beach, FL (US);
Timothy Jackson, Coral Springs, FL (US);
William L Zipoy, Austin, TX (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
An I/O controller for transferring data between a host processor and one or more I/O devices. This I/O controller includes a microprocessor, a direct memory access controller and a dual port storage unit, one port of which is coupled to the host processor I/O channel bus and the other port of which is coupled to the microprocessor bus. All data transfers are by way of the dual port storage unit. The I/O controller includes an interleaving mechanism for enabling concurrent performance of two different modes of data transfer between the host processor and the I/O controller. In particular, this interleaving mechanism enables host processor direct program control (DPC) data transfers to be performed at the same time that the I/O controller is busy doing cycle steal data transfers for a block of data. These DPC data transfers are accomplished without interrupting the cycle stealing operations.