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. 03, 1976
Filed:
Nov. 19, 1973
James A Katzman, San Jose, CA (US);
Yoshiro Yoshioka, San Jose, CA (US);
Amdahl Corporation, Sunnyvale, CA (US);
Abstract
A data processing system where transfers of information are made between I/O devices and system storage through channels is a channel unit having common apparatus shared among all the channels. The common apparatus includes a sequentially accessed state memory and a plurality of processors. The state memory includes a memory location for each channel. The processors have access to different parts of the state memory and perform functions in response to stored information. A data access processor controls transfers between system storage and the channel unit. A controller interface processor controls transfers between the channel unit and I/O devices. The quantity of information to be transferred for each channel is stored in the state memory. Each time a portion of the total transfer is completed, a count field in the state memory is updated. In one embodiment, only the low-order bits of the total count are stored in the state memory and the balance or high-order bits of the count are stored in channel memory.