Cache arrangements for data processing systems
AssigneeArm Limited
InventorsOlof Henrik Uhrenholt, Andrew Brookfield Swaine
Life of this patent
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Abstract
A data processing system is provided comprising a cache system configured to transfer data between a processor and memory system. The cache system comprises a cache. When a block of data that is stored in the memory in a compressed form is to be loaded into the cache, the block of data is stored into a group of one or more cache lines of the cache and the associated compression metadata for the compressed block of data is provided as separate side band data.
Claims19
A method of operating a data processing system, the data processing system comprising:
- a processor;
- a memory system;
- and
- a cache system configured to transfer data stored in the memory system to the processor for use by the processor when performing data processing operations and to transfer data from the processor to the memory system;
- the cache system comprising a cache configured to receive data from the memory and to provide data to the processor for use when performing data processing operations and to receive data from the processor for sending to the memory,
- the cache comprising a plurality of cache lines each able to store a respective data entry;
- the method comprising:
- when a block of data that is stored in the memory in a compressed form is to be loaded into the cache, the compressed block of data having a set of associated compression metadata:
- storing the block of data into a group of one or more cache lines of the cache;
- and
- providing the compression metadata for the block of data as separate side band data associated with a cache line of the group of one or more cache lines of the cache in which the block of data is stored.
A method of operating a data processing system, the data processing system comprising:
- a processor;
- and
- a memory system;
- the method comprising:
- when a block of data is to be stored in memory in a compressed form, the compressed block of data having a set of associated compression metadata:
- storing the block of data into a respective data structure in memory;
- and
- storing the compression metadata in a separate header data structure, the header data structure including one or more data fields, and wherein the compression metadata is stored in a data field that would in a different mode of operation be used for other information.
A data processing system comprising:
- a processor;
- a memory system;
- and
- a cache system configured to transfer data stored in the memory system to the processor for use by the processor when performing data processing operations and to transfer data from the processor to the memory system;
- the cache system comprising a cache configured to receive data from the memory and to provide data to the processor for use when performing data processing operations and to receive data from the processor for sending to the memory,
- the cache comprising a plurality of cache lines each able to store a respective data entry;
- the data processing system further including:
- a cache control circuit configured to:
- when a block of data that is stored in the memory in a compressed form is to be loaded into the cache, the compressed block of data having a set of associated compression metadata:
- store the block of data into a group of one or more cache lines of the cache;
- and
- obtain the compression metadata for the block of data as separate side band data.
A data processing system comprising:
- a processor;
- and
- a memory system;
- and
- a control circuit configured to:
- when a block of data is to be stored in memory in a compressed form, the compressed block of data having a set of associated compression metadata:
- store the block of data into a respective data structure in memory;
- and
- store the compression metadata in a separate header data structure, the header data structure including one or more data fields, and wherein the compression metadata is stored in a data field that would in a different mode of operation be used for other information.
Dependencies are inferred from the claim text.