Isolation devices for high performance solid state drives
View Patent ↗Systems and methods are provided for coupling multiple flash devices to a shared bus utilizing isolation switches within a SSD device. The SSD device is operable at a speed of about 400 MT/s or higher with high signal integrity. The SSD device includes a controller, a channel in electrical communication with the controller, a plurality of isolation devices in electrical communication with channel, and a plurality of flash memory devices, wherein each flash memory device is in electrical communication with the channel and controller through the one of the isolation devices.
1. A solid state device comprising:
an application specific integrated circuit (ASIC) controller having a port;
a plurality of flash memory devices, wherein each flash memory device is configured to be in electrical communication with the port associated with the ASIC controller; and
a plurality of isolation devices configured to electrically couple the port to one of the plurality of flash memory devices and to decouple the port from the rest of the plurality of flash memory devices.
2. The solid state device of claim 1 , wherein the plurality of isolation devices are arranged in a tree topology.
3. The solid state device of claim 2 , wherein the tree topology comprises a binary tree topology.
4. The solid state device of claim 1 , wherein the ASIC controller is configured to send a control signal to the plurality of isolation devices to cause the plurality of isolation devices to couple the port to the one of the plurality of flash memory devices and to decouple the port from the rest of the plurality of flash memory devices.
5. The solid state device of claim 1 , wherein at least one of the plurality of isolation devices comprises a multiplexor.
6. The solid state device of claim 1 , wherein at least one of the plurality of isolation devices comprises a field effect transistor switch.
7. The solid state device of claim 1 , wherein at least one of the plurality of isolation devices comprises an electrostatic discharge (ESD) protection circuit.
8. The solid state device of claim 1 , wherein at least one of the plurality of isolation devices is configured to electrically decouple one or more of the plurality of flash memory devices from the ASIC controller in response to an exception condition.
9. The solid state device of claim 1 , wherein at least one of the plurality of isolation devices is configured to receive a flash control data signal, a select command signal, and an output enable signal from the ASIC controller,
wherein the at least one of the plurality of isolation devices is configured to provide the flash control data signal and the select command signal to one of the plurality of flash memory devices when the output enable signal is in a first state, and
wherein the at least one of the plurality of isolation devices is configured to decouple the one of the plurality of flash memory devices from the ASIC controller when the output enable signal is in a second state.
10. The solid state device of claim 9 , wherein the at least one of the plurality of isolation devices is configured to receive the flash control data signal at one of: a rate of about 400 MT/s, or at a rate between about 400 MT/s and about 1000 MT/s.
11. The solid state device of claim 9 , wherein the controller is configured to provide the output enable signal in the second state in response to an exception condition.
12. The solid state device of claim 11 , wherein the exception condition includes a power supply disruption.
13. A circuit system comprising:
a memory controller electrically coupled to a channel, wherein the memory controller is configured to select one of a plurality of flash memory devices and to provide a control signal in response to the selection, and wherein the channel is configured to accommodate a data signal at a rate greater or equal to about 400 million transfers per second (MT/s); and
a multiplexing circuit electrically coupled to the channel and to the plurality of flash memory devices, wherein the multiplexing circuit is configured to receive the control signal from the memory controller and, in response, to couple the channel to the selected one of the plurality of flash memory devices, and wherein the multiplexing circuit is further configured to decouple each of the plurality of flash memory devices from the memory controller in response to an exception condition.
14. The circuit system of claim 13 , wherein the exception condition comprises a power supply disruption.
15. The circuit system of claim 13 , wherein the controller is configured to indicate the exception condition to the multiplexing circuit by sending an output enable signal to the multiplexing circuit.
16. The circuit system of claim 13 , wherein the multiplexing circuit comprises a plurality of isolation devices arranged in a tree topology, and wherein at least one of the plurality of isolation devices comprises an electrostatic discharge (ESD) protection circuit.
17. A method implemented in a solid state drive system comprising:
receiving a data control signal, a select command signal, and an output enable signal from a memory controller at an isolation device;
if the output enable signal is at a first enable state,
sending the data control signal from the isolation device to a first memory device when the select command signal is in a first selection state;
sending the data control signal from the isolation device to a second memory device when the select command signal is in a second selection state; and
if the output enable signal is at a second enable state,
decoupling the first memory device and the second memory device from the memory controller.
18. The method of claim 17 , wherein the output enable signal is received from the memory controller in response to a power supply disruption.
19. The method of claim 17 , wherein receiving the data control signal from the memory controller at the isolation device includes receiving the data control signal at one of: a rate of about 400 MT/s, or at a rate between about 400 MT/s and about 1000 MT/s.
20. The method of claim 17 , wherein decoupling the first memory device and the second memory device from the SSD controller includes decoupling the isolation device from a power supply.