Semiconductor device, data processing system, and semiconductor device control method

A semiconductor device comprising:

• a control unit configured to read compressed data stored in a memory in response to a read request for reading the compressed data from the memory, the read request including an address of data before compression;
• and
• a cache configured to store auxiliary information indicating a data length of the compressed data, the auxiliary information being stored in the memory together with the compressed data,
• wherein the compressed data is generated by compressing the data before compression in units of a predetermined data size, and is stored in a location of the memory specified by the address of the data before compression, and
• wherein, when reading the compressed data stored in the memory in response to the read request, the control unit:
• if the auxiliary information about the compressed data to be read is stored in the cache, reads from the cache the auxiliary information about the compressed data to be read, and reads from the memory the compressed data using the address included in the read request and the auxiliary information read from the cache,
• if the auxiliary information about the compressed data to be read is not stored in the cache, reads from the memory the auxiliary information about the compressed data to be read, stores in the cache the auxiliary information read from the memory, and reads from the memory the compressed data using the address included in the read request and the auxiliary information read from the memory.

A control method of the semiconductor device for reading compressed data stored in a memory using auxiliary information, wherein the semiconductor device comprises a cache, the auxiliary information indicates a data length of the compressed data and is stored in the memory together with the compressed data, the compressed data is generated by compressing data before compression in units of a predetermined data size and is stored in a location of the memory specified by an address of the data before compression, the control method comprising:

• generating a read request for reading the compressed data from the memory, the read request including the address of the data before compression;
• determining whether the auxiliary information about the compressed data to be read is stored in the cache in response to the read request;
• if the auxiliary information about the compressed data to be read is stored in the cache,
• reading from the cache the auxiliary information about the compressed data to be read;
• reading from the memory the compressed data using the address included in the read request and the auxiliary information read from the cache;
• if the auxiliary information about the compressed data to be read is not stored in the cache,
• reading from the memory the auxiliary information about the compressed data to be read;
• storing in the cache the auxiliary information read from the memory;
• and
• reading from the memory the compressed data using the address included in the read request and the auxiliary information read from the memory.