Nonvolatile memory device, read method for nonvolatile memory device, and memory system incorporating nonvolatile memory device
A method of performing a read operation on nonvolatile memory device comprises receiving a read command, receiving addresses, detecting a transition of a read enable signal, generating a strobe signal based on the transition of the read enable signal, reading data corresponding to the received addresses, and outputting the read data after the strobe signal is toggled a predetermined number of times.
1. A nonvolatile memory system, comprising:
a controller configured to program a latency option, the controller being configured to generate a read enable signal, a read command and a read address; and
a nonvolatile memory device configured to receive the latency option, the read enable signal, the read command and the read address,
wherein the nonvolatile memory device is configured to detect a toggling of the read enable signal,
the nonvolatile memory device is configured to generate a strobe signal in response to the toggling of the read enable signal,
the nonvolatile memory device is configured to output data to the controller after the strobe signal is toggled N times, N being a value related to the latency option,
the read enable signal remains constant while the read command and the read address are received by the nonvolatile memory device, and
the read enable signal is toggled after the read command and the read address are received by the nonvolatile memory device.
2. The nonvolatile memory system of claim 1 , wherein the nonvolatile memory device includes an address decoder configured to select a memory cell among a memory cell array in response to the read address.
3. The nonvolatile memory system of claim 1 , wherein the nonvolatile memory device includes a clock generator configured to generate a clock based on the read enable signal and the latency option.
4. The nonvolatile memory system of claim 3 , wherein the nonvolatile memory device includes a read and write circuit configured to read the data corresponding to the read address and transfer the data in response to the clock.
5. The nonvolatile memory system of claim 3 , wherein the clock generator includes:
a clock controller configured to generate a plurality of rising mask signals activated in synchronization with a rising edge of the read enable signal and the plurality of falling mask signals activated in synchronization with a falling edge of the read enable signal based on the latency option; and
a clock generating circuit configured to generate the clock in synchronization with the plurality of rising mask signals or the plurality of falling mask signals.
6. The nonvolatile memory system of claim 1 , wherein N is a positive integer equal to or greater than one.
7. The nonvolatile memory system of claim 1 , wherein the nonvolatile memory device is configured to detect the toggling of the read enable signal in response to the read command and the read address.
8. The nonvolatile memory system of claim 1 , wherein the nonvolatile memory system is a solid state drive (SSD).
9. A method of reading a nonvolatile memory device, comprising:
receiving a latency option;
receiving a read enable signal;
receiving a read command and a read address;
detecting a toggling of the read enable signal;
generating a strobe signal in response to the toggling of the read enable signal; and
outputting data after the strobe signal is toggled N times, N being a value related to the latency option,
wherein the read enable signal remains constant while the read command and the read address are received, and
the read enable signal is toggled after the read command and the read address are received.
10. The method of claim 9 , wherein N is a programmable value.
11. The method of claim 9 , wherein the outputting the data includes:
generating a delayed clock delayed from the read enable signal referring to the latency option; and
outputting the data in synchronization with the delayed clock.
12. The method of claim 11 , wherein the outputting the data includes:
generating a selection signal for selecting the data read from a plurality of sub-arrays sequentially in response to the delayed clock and the latency option; and
generating the strobe signal by delaying the read enable signal based on the latency option.
13. The method of claim 9 , further comprising generating at least one dummy address based on the read address.
14. The method of claim 9 , wherein the detecting a toggling of the read enable signal is performed in response to the read command and the read address.
15. A method of reading a nonvolatile memory device, comprising:
receiving a read enable signal;
receiving a read command and a read address;
detecting a toggling of the read enable signal;
generating a strobe signal in response to the toggling of the read enable signal; and
outputting data after the strobe signal is toggled N times, N being a positive integer equal to or greater than one,
wherein the read enable signal remains constant while the read command and the read address are received, and
the read enable signal is toggled after the read command and the read address are received.
16. The method of claim 15 , wherein N is a programmable value.
17. The method of claim 15 , further comprising receiving a latency option, wherein N is related to the latency option.
18. The method of claim 15 , further comprising generating at least one dummy address based on the read address.
19. The method of claim 15 , further comprising sensing a selected memory area and latching the data.
20. The method of claim 15 , further comprising generating at least one dummy address based on the read address.