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:
Oct. 18, 1994
Filed:
Jan. 10, 1992
Neal A Crook, Reading, GB;
Vincent G Gavin, Galway, IE;
Robert J Galuszka, Reading, GB;
John M Lenthall, Galway, GB;
Bipin Mistry, Edgware, GB;
Clinton Choi, London, GB;
Paul L Bruce, Basingstoke, GB;
Digital Equipment Corporation, Maynard, MA (US);
Abstract
An apparatus and method for supplying an address and data to an external memory device. The number of pins available for supplying the address is less than the number of address lines required at the external memory device. A register is used to store the high order bits of the address and is pre-loaded with a default page value. An output of the register is coupled to an address input of the external memory. If the high order bits of the address are equal to the default page value, a control device couples the data lines directly to the external memory device and a read or write operation follows. If the two values are different, a paging cycle is performed where the high order address bits are latched through the register to the address input of the external memory and then the data bits are coupled to the external memory device. If the default page value points to the most accessed portion of the external memory device, no paging is performed during access to that portion of the external memory and processing time is saved when reads or writes of data are made to that portion of the external memory.