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:
Aug. 08, 2000
Filed:
Jan. 13, 1998
William L Randolph, Durham, NC (US);
Stephen Camacho, Durham, NC (US);
Rhonda Cassada, Hillsborough, NC (US);
Mitsubishi Semiconductor America, Inc., Durham, NC (US);
Abstract
A multi-port RAM (MPRAM) having a SRAM and a DRAM. A global bus is arranged between the DRAM and the SRAM to provide bi-directional transfer of 256-bit data blocks between the SRAM and the DRAM. Two independent input/output ports are coupled to the SRAM to enable a user to write or read data to or from the SRAM and DRAM. Byte masking is provided for each of the ports to mask bytes of data supplied to the MPRAM. A write-per-bit (WPB) mask register is arranged between the ports and the SRAM to prevent unnecessary bits of input data from being written into the SRAM. A byte write enable (BWE) mask register is arranged between the SRAM and the DRAM to prevent unnecessary bytes of data from being transferred from the SRAM to the DRAM. Each of the mask registers may be loaded with mask data from both of the ports concurrently, or from any one of them.