Patent ID: 8171207

Claim:
A control method for storing a writing data into a hybrid density storage device, wherein the hybrid density storage device comprises a high density memory unit and a low density memory unit defining plural continuous blocks and a valid block range through a head pointer register and an tail pointer register for storing at least a valid data, and wherein an address stored in the head pointer register is directed to a block storing the newest valid data, and an address stored in the tail pointer register is directed to a block storing the oldest valid data, the control method comprising steps of: executing a hot data filter procedure, wherein a data length of the writing data is compared with a threshold for recognizing a property of the writing data; and allocating the high density memory unit or the low density memory unit of the hybrid density storage device for the writing data according to the property of the writing data by executing an adapting procedure and a data processing procedure; wherein the data processing procedure comprises redirecting the head pointer register to the block next to the block to which the head pointer register is previously directed, allocating the block to which the head pointer register is redirected for the writing data, erasing the valid data stored in the block directed by the tail pointer register, and redirecting the tail pointer register to the block next to the block to which the tail pointer register previously is directed, wherein the valid block range bounded by the head pointer register and the tail pointer register is fixed; wherein when the writing data is categorized as a hot data as the data length of the writing data is less than the threshold allocates the low density memory unit for the hot data; otherwise, allocates the high density memory unit for the writing data that is categorized as a cold data when the data length of the writing data is larger than the threshold.