US Patent 7724568 Memory device having read cache

A memory device comprises a non-volatile electrically alterable memory which is susceptible to read disturbance. The device has a control circuit for controlling the operation of the non-volatile memory. The device further has a first volatile cache memory. The first volatile cache memory is connected to the control circuit and is for storing data to be written to or read from the non-volatile memory, as cache for the memory device. The device further has a second volatile cache memory. The second volatile cache memory is connected to the control circuit and is for storing data read from the non-volatile memory as read cache for the memory device. Finally the control circuit reads data from the second volatile cache memory in the event of a data miss from the first volatile cache memory, and reads data from the non-volatile memory in the event of a data miss from the first and second volatile cache memories.