Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Multi-processor DRAM controller that prioritizes row-miss requests to stale banks










Image Number 7 for United States Patent #5745913.

Memory requests from multiple processors are re-ordered to maximize DRAM row hits and minimize row misses. Requests are loaded into a request queue and simultaneously decoded to determine the DRAM bank of the request. The last row address of the decoded DRAM bank is compared to the row address of the new request and a row-hit bit is set in the request queue if the row addresses match. The bank's state machine is consulted to determine if RAS is low or high, and a RAS-low bit in the request queue is set if RAS is low and the row still open. A row counter is reset for every new access but is incremented with a slow clock while the row is open but not being accessed. After a predetermined count, the row is considered "stale". A stale-row bit in the request queue is set if the decoded bank has a stale row. A request prioritizer reviews requests in the request queue and processes row-hit requests first, then row misses which are to a stale row. Lower in priority are row misses to non-stale rows which have been more recently accessed. Requests loaded into the request queue before the cache has determined if a cache hit has occurred are speculative requests and can open a new row when the old row is stale or closed.








 
 
  Recently Added Patents
RFID reader revocation checking using low power attached displays
Soybean cultivar CL1013663
Cosmetic composition based on a supramolecular polymer and a hyperbranched functional polymer
Multistable electromagnetic actuators
Searchlight
Voltage regulator with improved voltage regulator response and reduced voltage drop
Method of transmitting data using spatial multiplexing
  Randomly Featured Patents
Method and apparatus for selective material delivery via an intra-renal catheter
Endoprosthetic bone joint
Epoxy resins containing discotic mesogenic moieties
Transportation and storage cask for spent nuclear fuels
Method and apparatus for discovery of dynamic network services
Method of replacing an image sensor array
Method and structure for fabricating capacitor devices for integrated circuits
Aggregated network communication bandwidth management information display system
Crystalline anti-human IL-12 antibodies
Process for preparing fluorinated amino-nitriles