Hitachi, Ltd.

Masatsugu Oshimi

Junji Ogawa

Yoshihiro Oikawa

Yutaka Uematsu

Hiroshi Hirayama

Yasuhiro Ikeda

In a memory controller, command, address and data are allocated to transmit the command, the address and the data to each of the plurality of memory devices through the same bus signal line and an identification signal to identify the command, the address and the data on the bus signal line is allocated to a memory common signal line in common among the plurality of memory devices to transmit the identification signal. When the memory controller indicates the data through the identification signal so as to make a first memory device transfer the data through the bus signal line, the memory controller makes the data transfer by the first memory device suspended, indicates the command through the identification signal so as to issue the command to a second memory device, and indicates the address through the identification signal so as to issue the address to the second memory device.

Memory controller, memory control method and semiconductor storage apparatus

A storage apparatus includes a non-volatile memory and a controller to determine whether or not to compress data at a time when a non-volatile memory device receives the data from a host apparatus. A storage controller transmits a specified logical address range, an update frequency level of the specified logical address range, and specified data to a device controller. The update frequency level may indicate whether data is Hot or Cold. On the basis of the update frequency level of the specified logical address range, the device controller determines whether to compress the specified data. When a determination is made to compress the specified data, the device controller compresses the specified data to generate compressed data, and writes the compressed data into a non-volatile memory which may be a flash memory device. A degradation rank of physical blocks in the flash memory may include at least Young and Old. Reclamation processing including selecting a migration destination on the basis of the updated frequency level may also be performed. When a determination is made not to compress the specified data, the device controller writes the specified data into the non-volatile memory.

Storage apparatus and non-volatile memory device including a controller to selectively compress data based on an update frequency level

This nonvolatile memory device has a blockwise-erase nonvolatile memory including a plurality of physical areas, and also has a memory controller which transmits one of a plurality of types of commands to the nonvolatile memory. After an erase command to erase one of the physical areas has been transmitted, but before a response to that erase command is received, the memory controller determines whether to suspend the ongoing erasure of the physical area, on the basis of whether there is a command to be transmitted and/or on the basis of the degree of deterioration of the physical area being erased. If the determination is affirmative, the memory controller transmits a command to the nonvolatile memory to suspend the erasure.

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Kanagawa, Japan

Masatsugu Oshimi