IP Library › Granted Patent US 8,380,934
Granted Patent B2
US 8,380,934 · App. 12/706,362 · Granted Feb 19, 2013

Cache device

Inventor: Gen Tsukishiro (Kasugai, JP)
Assignee: Fujitsu Semiconductor Limited
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Quick Facts
Patent No.
US 8,380,934
App. No.
12/706,362
Granted
Feb 19, 2013
Kind
B2
Abstract

A cache device interposed between a processor and a memory device, including: a cache memory storing data from the memory device; a buffer holding output data output from the processor; a control circuit determining, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in the buffer in response to the access request, outputting a read request for reading the data in a line containing data requested by the access request from the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the buffer into the cache memory.

Claims (12)

1. A cache device interposed between a processor and a memory device, comprising:

a cache memory to store data from the memory device;

a plurality of buffers to hold output data output from the processor; and

a control circuit to determine, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in one of the plurality of buffers in response to the request to access the memory device, outputting a read request for reading the data in a line containing data requested by the request to access the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the one of the plurality of buffers into the cache memory,

wherein the plurality of buffers, each including the data in a different line,

wherein: if an address of the output data is not within the address range of the data in the line included in the one of the plurality of buffers, another one of the plurality of buffers is alternately selected, the address of the output data being within the address range of the data in the line included in another one of the plurality of buffers.

2. A cache device interposed between a processor and a memory device, comprising:

a cache memory to store data from the memory device;

a buffer to hold output data output from the processor; and

a control circuit to determine, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in the buffer in response to the request to access the memory device, outputting a read request for reading the data in a line containing data requested by the request to access the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the buffer into the cache memory,

wherein: the amount of the output data transferred from the buffer to the cache memory is set equal to the capacity of the line; and when the access request is a write access request and the write access request results in a cache miss, data read from the memory device for the cache miss is cancelled.

3. The cache device according claim 1 , wherein: the amount of the output data transferred from the buffer to the cache memory is set equal to the capacity of the line; and when the access request is a write access request and the write access request results in a cache miss, data read from the memory device for the cache miss is cancelled.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2015
From: FUJITSU SEMICONDUCTOR LIMITED
To: SOCIONEXT INC.
Reel/Frame 035508/0637 →
CHANGE OF NAME Recorded Jul 22, 2010
From: FUJITSU MICROELECTRONICS LIMITED
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 024748/0328 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 19, 2010
From: TSUKISHIRO, GEN
To: FUJITSU MICROELECTRONICS LIMITED
Reel/Frame 023961/0535 →
Priority Claims (1)
JP 2009-034588 · Feb 17, 2009 · national
Continuity (1)
Related Publication 20100211746A1 · Aug 19, 2010