Semiconductor storage device
View Patent ↗A nonvolatile memory device includes a memory cell array, a control circuit, a voltage boost circuit, a timer circuit, a discharge circuit and a sensor circuit. The control circuit generates an erase execution (EE) signal in response to an erase command (EC) signal, stops the EE signal and generates a discharge control (DC) signal in response to an erase termination (ET) signal, stops the DC signal in response to a discharge termination (DT) signal, and stops the EE signal and the DC signal in response to a reset signal. The boost circuit provides high voltage in response to the EE signal. The timer circuit generates the ET signal after receiving the EE signal. The discharge circuit discharges the high voltage and the sensor is enabled in response to the DC signal or the reset signal. The sensor generates the DT signal when the high voltage drops to a predetermined voltage.
1. A nonvolatile memory device comprising:
a memory cell array having a plurality of nonvolatile memory cells capable of erasing data by applying high voltage;
a control circuit generating an erase execution signal in response to an erase command signal received thereto, the control circuit stopping the erase execution signal and generating a discharge control signal in response to an erase termination signal received thereto, the control circuit stopping the discharge control signal in response to a discharge termination signal received thereto, the control circuit stopping the erase execution signal and the discharge control signal in response to a reset signal received thereto;
a voltage boost circuit providing high voltage to the memory cell for erasing data in response to the erase execution signal;
a timer circuit generating the erase termination signal when a predetermined time elapses after receiving the erase execution signal;
a discharge circuit discharging the high voltage supplied from the voltage boost circuit in response to either one of the discharge control signal and the reset signal received thereto; and
a sensor circuit being enabled in response to either one of the discharge control signal and the reset signal received thereto, the sensor circuit generating the discharge termination signal when the high voltage drops down to a predetermined voltage.
2. A nonvolatile memory device according to claim 1 , further comprising a word line decoder for providing the high voltage to the memory cell array.
3. A nonvolatile memory device according to claim 1 , wherein the control circuit includes a plurality of flip-flops and a plurality of gate circuits.
4. A nonvolatile memory device according to claim 1 , wherein the timer circuit includes an oscillator for generating a clock signal and a counter for counting the clock signal in response to the erase execution signal.
5. A nonvolatile memory device according to claim 1 , wherein the control circuit further generating an erase starting signal in response to the reset signal and the erase command signal.
6. A nonvolatile memory device according to claim 5 , wherein the wherein the timer circuit includes an oscillator for generating a clock signal in response to the erase starting signal and a counter for counting the clock signal in response to the erase execution signal.
7. A nonvolatile memory device comprising: a memory cell array having a plurality of nonvolatile memory cells capable of erasing data by applying high voltage;
a control circuit generating an erase execution signal in response to an erase command signal received thereto, the control circuit stopping the erase execution signal and generating a discharge control signal in response to an erase termination signal received thereto, the control circuit stopping the discharge control signal in response to a discharge termination signal received thereto, the control circuit stopping the erase execution signal and the discharge control signal in response to a reset signal received thereto;
a pulse circuit generating a pulse signal having a predetermined pulse width in response to the reset signal;
a voltage boost circuit providing high voltage to the memory cell for erasing data in response to the erase execution signal;
a timer circuit generating the erase termination signal when a predetermined time elapses after receiving the erase execution signal;
a discharge circuit discharging the high voltage supplied from the voltage boost circuit in response to either one of the discharge control signal and the reset signal received thereto; and
a sensor circuit being enabled in response to either one of the discharge control signal and the pulse signal received thereto, the sensor circuit generating the discharge termination signal when the high voltage drops down to a predetermined voltage.
8. A nonvolatile memory device according to claim 7 , further comprising a word line decoder for providing the high voltage to the memory cell array.
9. A nonvolatile memory device according to claim 7 , wherein the control circuit includes a plurality of flip-flops and a plurality of gate circuits.
10. A nonvolatile memory device according to claim 7 , wherein the timer circuit includes an oscillator for generating a clock signal and a counter for counting the clock signal in response to the erase execution signal.
11. A nonvolatile memory device according to claim 7 , wherein the control circuit further generating an erase starting signal in response to the reset signal and the erase command signal.
12. A nonvolatile memory device according to claim 11 , wherein the wherein the timer circuit includes an oscillator for generating a clock signal in response to the erase starting signal and a counter for counting the clock signal in response to the erase execution signal.
13. A nonvolatile memory device comprising:
a memory cell array having a plurality of nonvolatile memory cells capable of erasing data by applying high voltage;
a control circuit generating an erase execution signal in response to an erase command signal received thereto, the control circuit stopping the erase execution signal and generating a discharge control signal in response to either one of a reset signal and an erase termination signal received thereto, the control circuit stopping the erase execution signal and the discharge control signal in response to a discharge termination signal received thereto;
a voltage boost circuit providing high voltage to the memory cell for erasing data in response to the erase execution signal;
a timer circuit generating the erase termination signal when a predetermined time elapses after receiving the erase execution signal;
a discharge circuit discharging the high voltage supplied from the voltage boost circuit in response to the discharge control signal received thereto; and
a sensor circuit being enabled in response to the discharge control signal received thereto, the sensor circuit generating the discharge termination signal when the high voltage drops down to a predetermined voltage.
14. A nonvolatile memory device according to claim 13 , further comprising a word line decoder for providing the high voltage to the memory cell array.
15. A nonvolatile memory device according to claim 13 , wherein the control circuit includes a plurality of flip-flops and a plurality of gate circuits.
16. A nonvolatile memory device according to claim 13 , wherein the timer circuit includes an oscillator for generating a clock signal and a counter for counting the clock signal in response to the erase execution signal.
17. A nonvolatile memory device according to claim 13 , wherein the control circuit further generating an erase starting signal in response to the reset signal and the erase command signal.
18. A nonvolatile memory device according to claim 17 , wherein the wherein the timer circuit includes an oscillator for generating a clock signal in response to the erase starting signal and a counter for counting the clock signal in response to the erase execution signal.