Electronic device with cache memory and method of operating the same
An electronic device with a cache memory and a method of operating the electronic device are provided. The electronic device includes a cache memory including a plurality of cache lines each of which includes a first area with at least one storage space and a second area with at least one storage space, where the at least one storage space of the first area has a first size and the at least one storage space of the second area has a second size different from the first size, and a cache controller for storing the data requested for storage in one of the storage spaces of the first or second area, according to a compression factor associated with the data requested for storage when a request is made to store data in the cache memory.
1. An electronic device comprising:
a cache memory including a plurality of cache lines each of which includes a reservation area and a main area with at least one storage space that has a size less than a predetermined size of data storage; and
a cache controller configured to:
compress the data requested to be stored in the cache memory if a request is made to store data in the cache memory,
determine whether the compressed data is equal to or less than the size of one of the at least one storage space of the main area,
store the compressed data in one of the storage spaces of the main area if the compressed data is equal to or less than the size of the at least one storage space of the main area,
wherein the cache controller is further configured to:
divide, the data requested for storage into divided parts of data if the compressed data is greater than the size of one of the storage spaces of the main area and the size of the divided part of data is equal to or less than the size of one of the storage space of the main area and the reservation area, and
store one divided part of data in one of the storage spaces of the main area and the other in one of the storage spaces of the reservation area without compression.
2. The electronic device of claim 1 , wherein the cache memory comprises:
a cache data memory configured to store the data requested for storage, the cache data memory including the main area and the reservation area; and
a cache tag, including address information of data stored in the cache data memory and status information, configured to map information about the divided parts of data stored in the main area and reservation area.
3. The electronic device of claim 1 ,
wherein the size of one storage space of the main area and the size of one storage space of the reservation area are added to produce a summation; and
wherein the summation is the predetermined size of data storage.
4. The electronic device of claim 3 , wherein the size of one storage space of the main area is identical to that of one storage space of the reservation area.
5. The electronic device of claim 2 , wherein the cache controller comprises:
a compression unit configured to compress the data requested to be stored in the cache memory;
a restoration unit configured to restore compressed and stored data to the original data if a request is made to read data;
a division unit configured to divide data that is not compressed to a size equal to or less than the size of one storage space of the main area; and
a combining unit configured to combine divided, stored data with each other if a request is made to read data from the cache memory.
6. The electronic device of claim 5 , wherein the combining unit is further configured to detect a location in the reservation area where data to be combined with data stored in the main area is stored if combining the divided, stored data with each other through the mapping information.
7. A method of managing a cache memory with a plurality of cache lines each of which includes a reservation area and a main area with at least one storage space that has a size less than a predetermined size of data storage, the method comprising:
detecting a request is made to store data in the cache memory;
compressing the data requested for storage;
determining whether the compressed data is equal to or less than the size of one of the storage spaces of the main area;
storing the compressed data in one of the storage spaces of the main area, if the compressed data is equal to or less than the size of one of the storage spaces of the main area;
dividing the data requested for storage into divided parts of data if the compressed data is greater than the size of one of the storage spaces of the main area and the size of the divided part of data is equal to or less than the size of one of the storage spaces of the main area and the reservation area; and
storing one divided part of data in one of the storage spaces of the main area and the other in one of the storage spaces of the reservation area without compression.
8. The method of claim 7 , further comprising:
detecting a request to read data from the cache memory;
determining whether the data requested to be read is compressed;
combining divided parts of data stored in the main area and reservation area with each other and reading the combined data if the data requested to be read is not compressed; and
restoring compressed data stored in the main area and reading the restored data if the data requested to be read is compressed.
9. The method of claim 8 , wherein combining divided parts of data stored in the main area and reservation area with each other comprises:
detecting a location in the reservation area where data to be combined with data stored in the main area is stored based on the mapping information.