NAND switch
In a memory system, a switch is connected between a controller and multiple non-volatile storage units, where the switch comprises first and second pins, a data bus, and a plurality of enable outputs. Each of the enable outputs of the switch is connected to an enable input of one of the non-volatile storage units. The switch is configured to transmit a signal to enable a communication path between the controller and one of the non-volatile storage units and to receive data over the data bus to be stored in one of the non-volatile storage units when the first and second pins are not asserted. In addition, the switch is configured to receive a command to be executed by one of the non-volatile storage units when the first pin is not asserted and the second pin is asserted. The switch is also configured to receive an address of a storage location within one of the non-volatile storage units when the first pin is asserted and the second pin is not asserted.
1. A memory system comprising:
a controller configured with a first enable output and a data output;
a plurality of non-volatile storage devices, each configured with an enable input and a data input; and
a first switch configured between the controller and a first set of the plurality of non-volatile storage devices, with
a first enable input that is connected to the first enable output of the controller,
a first data input that is connected to the data output of the controller,
a first data output that is connected to the data input of each of the first set of non-volatile storage devices, and
a plurality of enable outputs, each of the enable outputs being connected to the enable input of one of the first set of non-volatile storage devices,
wherein in response to the controller asserting the first enable output and transmitting select data which indicates one of the enable outputs of the first switch connected to an enable input of a first non-volatile storage device among the first set of non-volatile storage devices,
the first switch enables a first communication path between the controller and the first non-volatile storage device, and transmits a command and an address of the first non-volatile storage device which are received from the controller, to a data input of the first non-volatile storage device.
2. The memory system of claim 1 , wherein
the controller is further configured with a second enable output,
the memory system further comprises
a second switch configured between the controller and a second set of the plurality of non-volatile storage devices, with
a second enable input that is connected to the second enable output of the controller,
a second data input that is connected to the data output of the controller,
a second data output that is connected to the data input of each of the second set of non-volatile storage devices, and
a plurality of enable outputs, each of the enable outputs being connected to the enable input of one of the second set of non-volatile storage devices, and
wherein in response to the controller asserting the second enable output and transmitting select data which indicates one of the enable outputs of the second switch connected to an enable input of a second non-volatile storage device among the second set of the plurality of non-volatile storage devices,
the second switch enables a second communication path between the controller and the second non-volatile storage device, and transmits a command and an address of the second non-volatile storage device which are received from the controller, to a data input of the second non-volatile storage device.
3. The memory system of claim 1 , wherein
the controller further comprises a first enablement pin and a second enablement pin, and
the first switch further comprises
a third enablement pin that is connected to the first enablement pin of the controller and
a fourth enablement pin that is connected to the second enablement pin of the controller.
4. The memory system of claim 3 , wherein
the controller is configured to
assert both of the first and second enablement pins during a first clock cycle, and
transmit the select data through the data output during a second clock cycle that is subsequent to the first clock cycle.
5. The memory system of claim 3 , wherein
the first switch is further configured with a selection register that stores a value of the select data that determines which of the enable outputs of the first switch is asserted.
6. The memory system of claim 3 , wherein
the first switch is configured to:
receive data to be stored in the first non-volatile storage device through the first data input when the first and second enablement pins are not asserted;
receive a command to be executed by the first non-volatile storage device when the first enablement pin is not asserted and the second enablement pin is asserted; and
receive an address of a storage location within the first non-volatile storage device when the first enablement pin is asserted and the second enablement pin is not asserted.
7. The memory system of claim 1 , wherein
one of the plurality of the enable outputs of the first switch is asserted based on the select data transmitted from the controller.
8. A method of performing read operation and write operation in a memory system having a controller connected to a plurality of non-volatile storage devices by way of a first switch including a first data input and a plurality of enable outputs, wherein each enable output is connected to an enable input of one of a first set of the non-volatile storage devices and the first data input is connected to a data output of the controller,
the method comprising:
asserting a first enable output of the controller, that is coupled to a first enable input of the first switch;
transmitting, from the controller to the first switch, select data which indicates one of the enable outputs of the first switch connected to an enable input of a first non-volatile storage device among the first set of the non-volatile storage devices;
enabling a first communication path between the controller and the first non-volatile storage device; and
transmitting, from a first data output of the first switch to a data input of the first non-volatile storage device, a command and an address of the first non-volatile storage device which are received from the controller.
9. The method of claim 8 , wherein
the memory system further comprises a second switch including a second data input and a plurality of enable outputs, wherein each enable output is connected to an enable input of one of a second set of the non-volatile storage devices and the second data input is connected to the data output of the controller, and
the method further comprises:
asserting a second enable output of the controller, that is coupled to a second enable input of the second switch;
transmitting, from the controller to the second switch, select data which indicates one of the enable outputs of the second switch connected to an enable input of a second non-volatile storage device among the second set of the non-volatile storage devices;
enabling a second communication path between the controller and the second non-volatile storage device; and
transmitting, from a second data output of the second switch to a data input of the second non-volatile storage device, a command and an address of the second non-volatile storage device which are received from the controller.
10. The method of claim 8 , wherein
the controller further comprises a first enablement pin and a second enablement pin, and
the first switch further comprises
a third enablement pin that is connected to the first enablement pin of the controller and
a fourth enablement pin that is connected to the second enablement pin of the controller.
11. The method of claim 10 , further comprising:
asserting both of the first and second enablement pins during a first clock cycle, wherein
the select data is transmitted through the data output during a second clock cycle that is subsequent to the first clock cycle.
12. The method of claim 10 , wherein
the first switch is further configured with a selection register that stores a value of the select data that determines which of the enable outputs of the first switch is asserted.
13. The method of claim 10 , further comprising:
receiving data to be stored in the first non-volatile storage device through the first data input when the first and second enablement pins are not asserted;
receiving a command to be executed by the first non-volatile storage device when the first enablement pin is not asserted and the second enablement pin is asserted; and
receiving an address of a storage location within the first non-volatile storage device when the first enablement pin is asserted and the second enablement pin is not asserted.
14. The method of claim 8 , further comprising:
asserting one of the plurality of the enable outputs of the first switch based on the select data transmitted from the controller.
15. A memory system comprising:
a controller configured with a first chip enable output and a data output;
a first switch configured with
a first chip enable input that is connected to the first chip enable output of the controller,
a first data input that is connected to the data output of the controller,
a first data output, and
multiple chip enable outputs; and
a first set of multiple non-volatile storage devices each configured with
a chip enable input that is connected to one of the chip enable outputs of the first switch, and
a data input that is connected to the first data output of the first switch,
wherein the first switch is configured between the controller and the first set of multiple non-volatile storage devices, and
wherein in response to the controller asserting the first chip enable output and transmitting select data that indicates one of the chip enable outputs of the first switch connected to the chip enable input of a first non-volatile storage device among the first set of multiple non-volatile storage devices,
the first switch enables a first communication path between the controller and the first non-volatile storage device, and transmits a command and an address of the first non-volatile storage device which are received from the controller, to a data input of the first non-volatile storage device.
16. The memory system of claim 15 , wherein
the controller is further configured with a second chip enable output,
the memory system further comprises:
a second switch configured with
a second chip enable input that is connected to the second chip enable output of the controller,
a second data input that is connected to the data output of the controller,
a second data output, and
multiple chip enable outputs; and
a second set of multiple non-volatile storage devices each configured with
a chip enable input that is connected to one of the chip enable outputs of the second switch, and
a data input that is connected to the second data output of the second switch,
wherein the second switch is configured between the controller and the second set of multiple non-volatile storage devices, and
wherein in response to the controller asserting the second chip enable output and transmitting select data that indicates one of the chip enable outputs of the second switch connected to the chip enable input of a second non-volatile storage device among the second set of multiple non-volatile storage devices,
the second switch enables a second communication path between the controller and the second non-volatile storage device, and transmits a command and an address of the second non-volatile storage device which are received from the controller, to a data input of the second non-volatile storage device.
17. The memory system of claim 15 , wherein
the controller further comprises a first enablement pin and a second enablement pin, and
the first switch further comprises
a third enablement pin that is connected to the first enablement pin of the controller and
a fourth enablement pin that is connected to the second enablement pin of the controller.
18. The memory system of claim 15 , wherein
one of the multiple chip enable outputs of the first switch is asserted based on the select data transmitted from the controller.