Combining presence detect pin with device management bus reset and power disable
Provided are devices, systems and methods relating to controller interactions with storage. One embodiment includes an apparatus comprising a controller for communication with a storage device through a signal line, wherein the controller is configured to detect a first signal on the signal line indicating the presence of the storage device on the signal line, and provide a second signal on the signal line to reset the storage device after a detection that the first signal indicates the presence of the storage device. Other embodiments are described and claimed.
1. An apparatus comprising:
a controller for communication with a storage device through a signal line;
wherein the controller is configured to:
detect a first signal on the signal line indicating a presence of the storage device on the signal line;
provide a second signal on the signal line to reset the storage device in response to an event, after a detection that the first signal indicates the presence of the storage device, wherein the second signal is held for a first time to reset the storage device; and
wherein the second signal is held for a second time to perform a power down of the storage device.
2. The apparatus of claim 1 , wherein the controller is configured to ignore the presence of the storage device during a time when the controller provides the second signal on the signal line to reset the storage device.
3. The apparatus of claim 1 , further comprising a resistor configured to be in communication with the signal line.
4. The apparatus of claim 3 , further comprising a transistor configured to be in communication with the signal line.
5. A system comprising:
a host;
a controller for communication between the host and a storage device; and
a signal line connecting the controller and the storage device;
wherein the controller is configured to:
detect a first signal on the signal line to indicate a presence of the storage device on the signal line;
provide a second signal on the signal line to reset the storage device in response to an event, after a detection that the first signal indicates the presence of the storage device, wherein the second signal is held for a first time to reset the storage device; and
wherein the second signal is held for a second time to perform a power down of the storage device.
6. The system of claim 5 , wherein the controller is further configured to ignore the presence of the storage device during a time when the controller provides the second signal to reset the storage device.
7. The system of claim 5 , wherein the host includes a first resistor in communication with the signal line, wherein the storage device includes a second resistor in communication with the signal line, and wherein the first resistor has a greater resistance than the second resistor.
8. The system of claim 7 , wherein the host includes a transistor in communication with the signal line.
9. The system of claim 5 , further comprising:
an additional controller for communication between the host and an additional storage device;
an additional signal line to connect the additional controller and the additional storage device;
the additional controller configured to detect a first signal on the additional signal line that indicates a presence of the additional storage device on the additional signal line; and
the additional controller configured to provide a second signal on the additional signal line to reset the additional storage device after a detection that the first signal indicates the presence of the additional storage device.
10. An apparatus comprising:
a storage device for communication with a controller through a signal line;
wherein the storage device is configured so that a first signal is provided on the signal line that indicates a presence of the storage device;
wherein the storage device is configured to receive from the controller a second signal on the signal line to reset the storage device in response to an event, wherein the second signal is held for a first time to reset the storage device; and
wherein the second signal is held for a second time to perform a power down of the storage device.
11. The apparatus of claim 10 , further comprising a resistor in the storage device, the resistor configured to be in communication with the signal line.
12. The storage device of claim 10 , wherein the storage device is configured to power down in response to the signal line holding the second signal for a predetermined amount of time.
13. A method for communicating between a host and a storage device, comprising:
configuring a controller for the host to detect a first signal indicating a presence of the storage device on a signal line between the controller for the host and the storage device;
configuring the controller to reset the storage device in response to an event by providing a second signal on the signal line after detecting the first signal indicating the presence of the storage device, wherein the second signal is held for a first time to reset the storage device; and
configuring the controller so that the second signal is held for a second time to perform a power down of the storage device.
14. The method of claim 13 , further comprising configuring the controller to ignore the presence of the storage device during a time when the controller is providing the second signal to reset the storage device.
15. The method of claim 13 , further comprising configuring the host to include a first resistor in communication with the signal line, and configuring the storage device to include a second resistor in communication with the signal line, wherein the first resistor has a greater resistance than the second resistor.
16. The method of claim 15 , further comprising configuring the host to include a transistor in communication with the signal line.