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:
Jul. 25, 1989
Filed:
Apr. 03, 1987
Dale E Gulick, Austin, TX (US);
Terry G Lawell, Austin, TX (US);
Charles Crowe, Germantown, TN (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A data link controller (DLC) 52 is disclosed which employs buffers (100,106) on both receive and transmit sides. These last-in, first-out buffers contain a position indicating that a character is the last one of a packet. In this way, a user need not monitor reception or transmission on a character-by-character basis, but need only concern themselves with packets. The receive and transmit FIFO's generate requests for more characters by monitoring the number of characters stored and thereby automatically receive and transmit characters without processor intervention. A four-stage mechanism (600,602,604,606,608,610,612,614) permits monitoring of multiple contiguous frames (back-to-back frames) received. Control of the DLC is provided by status and control registers (112,212) which are accessible to the user via a microprocessor interface (50). Particular registers have bit positions monitoring status conditions in such a manner that the most-probable one of a set of conditions compries the least-significant bit position, while the least-probable condition occupies the most-significant bit position. This affords simple shift and test technique for monitoring status conditions.