Storage device and server device
According to one embodiment, a storage device includes a memory, a controller, an interface unit, a switch, and a switch control unit. The memory stores data. The controller is configured to control writing of data to the memory and reading of data from the memory. The interface unit includes a first terminal, a second terminal, and a third terminal. The first terminal has an electrical status different between a case where the storage device and a first device are connected, and a case where the storage device and a second device are connected. Through the second terminal, voltage is applied by the first device to the storage device in the case where the storage device and the first device are connected, and a control signal is input from the second device to the storage device in the case where the storage device and the second device are connected. Through the third terminal, power is supplied to the storage device. The switch switches a connection status and a disconnection status. In the connection status, the third terminal and the controller are electrically connected. In the disconnection status, the third terminal and the controller are electrically disconnected. The switch control unit is configured to control the switch to switch the connection status and the disconnection status based on electrical statuses of the first terminal and the second terminal.
1. A storage device comprising:
a memory that stores data;
a controller configured to control writing of data to the memory and reading of data from the memory;
an interface unit that includes a first terminal, a second terminal, and a third terminal,
the first terminal having an electrical status different between a case where the storage device and a first device are connected, and a case where the storage device and a second device are connected,
the second terminal being a terminal through which voltage is applied by the first device to the storage device in the case where the storage device and the first device are connected, and a terminal through which a control signal is input from the second device to the storage device in the case where the storage device and the second device are connected,
the third terminal being a terminal through which power is supplied to the storage device;
a switch that switches a connection status and a disconnection status, the connection status representing a status in which the third terminal and the controller are electrically connected, the disconnection status representing a status in which the third terminal and the controller are electrically disconnected; and
a switch control unit configured to control the switch to switch the connection status and the disconnection status based on electrical statuses of the first terminal and the second terminal.
2. The storage device according to claim 1 , wherein
the switch control unit is configured to control the switch based on the electrical status of the first terminal such that in a case where the storage device and the first device are connected, the switch enters the connection status, and in a case where the storage device and the second device are connected, the connection status and the disconnection status of the switch are switched according to the control signal.
3. The storage device according to claim 1 wherein
in a case where the storage device and a third device are connected, power is supplied from the third device to the storage device through the third terminal, and the power and the control signal are not input to the storage device from the third device through the second terminal, and
the switch control unit is configured to control the switch based on the electrical status of the second terminal such that in a case where the storage device and the third device are connected, the switch enters the connection status.
4. The storage device according to claim 1 , wherein
a high level of the potential of the control signal corresponds to the disconnection status of the switch, and a low level of the potential of the control signal corresponds to the connection status of the switch, and
in a case where the potential of the first terminal is at the high level and the potential of the second terminal is at the high level, the switch is controlled to enter the connection status, and in a case where the potential of the first terminal is at the low level or at another level different from the high level and the low level and the potential of the second terminal is at the high level, the switch is controlled to enter the disconnection status.
5. The storage device according to claim 4 , wherein
in a case where the potential of the second terminal is at the low level or another level different from the high level and the low level, the switch control unit controls the switch to enter the connection status regardless of the potential of the first terminal.
6. The storage device according to claim 1 , wherein
the switch control unit includes a logical circuit which performs a logical operation based on levels of the potentials of the first terminal and the second terminal.
7. The storage device according to claim 6 , wherein
the switch control unit includes a first pull-down circuit and a second pull-down circuit, the first pull-down circuit including a first resistance connected between the first terminal and a ground portion, the second pull-down circuit including a second resistance connected between the second terminal and the ground portion.
8. The storage device according to claim 6 , wherein
the logical circuit includes a NOT circuit and an AND circuit,
the NOT circuit inverses the high level and the low level of the potential of the first terminal and outputs the potential,
the AND circuit outputs a logical product of the level of the output potential of the NOT circuit and the level of the potential of the second terminal, and
the switch control unit is configured to control the switch to enter the disconnection status in a case where the level of the output potential of the AND circuit is at the low level, the switch control unit being configured to control the switch to enter the connection status in a case where the level of the output potential of the AND circuit is at the high level.
9. The storage device according to claim 1 , wherein
the switch control unit is configured to operate by the power supplied through the third terminal.
10. The storage device according to claim 9 , comprising:
a potential adjusting unit provided between the third terminal and the switch control unit, the potential adjusting unit being configured to adjust the potential of the third terminal to be the potential of a power source of the switch control unit.
11. The storage device according to claim 1 , comprising:
a delay circuit provided between the switch control unit and the switch.
12. The storage device according to claim 1 , wherein
the first terminal is P 1 pin or P 2 pin of a power source interface in the SAS3 standard,
the second terminal is P 3 pin of the power source interface, and
the third terminal is any one of P 7 pin, P 8 pin, P 9 pin, P 13 pin, P 14 pin, P 15 pin of the power source interface.
13. The storage device according to claim 12 , wherein
the first device is in conformity to the SAS1 standard, the SAS2 standard, or the SAS2.1 standard,
the second device is in conformity to the SAS3 standard, and
the control signal is a power disable signal.
14. The storage device according to claim 12 , wherein
the third device is in conformity to the SAS3 standard, and does not correspond to control using a power disable signal.
15. A server device comprising the storage device according to claim 1 .
16. A storage device comprising:
a memory that stores data;
a controller configured to control writing of data to the memory and reading of data from the memory;
an interface unit that includes a first terminal, a second terminal, and a third terminal,
the first terminal having an electrical status different between a case where the first terminal is connected to the first device, and a case where the first terminal is connected to the second device,
the second terminal being a terminal to which a control signal is input from the second device,
the third terminal being a terminal through which power is supplied from the second device to the storage device;
a switch configured to switch a connection status and a disconnection status based on the control signal, the connection status representing a status in which the third terminal and the controller are electrically connected, the disconnection status representing a status in which the third terminal and the controller are electrically disconnected; and
a switch control unit configured to control the switch to switch the connection status and the disconnection status based on electrical statuses of the first terminal and the second terminal.