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. 04, 1997
Filed:
Apr. 26, 1995
Richard A Gahan, County Galway, IE;
Eugene O'Neill, Galway, IE;
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A data processing system comprising a main memory 10 with a 32-bit longword data bus 11 and an address bus 12, and a link unit 20 using 16-bit shortwords. The link unit has two shortword memories 26 and 28 for descriptor and message shortwords. Descriptor shortwords are exchange individually with the memory 10, residing in the lower halves of longword locations; message shortwords are exchanged with the memory 10 through a concatenation and deconcatenation unit 40 so that they are stored in pairs in longword locations. Unit 20 passes descriptor addresses (with top bit 1) from a register 25 and message addresses (with top bit 0) from a register 27 to the main memory through address processing means 36, which comprises a multiplexer 43 with its two data inputs fed with two versions of the address with a 1-bit shift between them. The top address bit controls the multiplexer, so that the main memory address steps by 1 for every step of a descriptor address or every second step of a message word address.