阅读说明：本技术 展频频率产生器、存储器储存装置及信号产生方法 (Spread spectrum frequency generator, memory storage device and signal generation method ) 是由 张智凯 于 2019-09-17 设计创作，主要内容包括：本发明提供一种展频频率产生器,其包括频率产生电路、阻抗组件及控制电路。所述阻抗组件连接至所述频率产生电路的阻抗端。所述控制电路用以提供控制信号至所述阻抗组件以于所述阻抗端产生第一电压。所述频率产生电路用以根据所述第一电压于所述频率产生电路的振荡端产生展频频率信号。此外,本发明也提供一种存储器储存装置及信号产生方法。(The invention provides a spread spectrum frequency generator, which comprises a frequency generating circuit, an impedance component and a control circuit. The impedance component is connected to an impedance terminal of the frequency generation circuit. The control circuit is used for providing a control signal to the impedance component so as to generate a first voltage at the impedance end. The frequency generation circuit is used for generating a spread spectrum frequency signal at an oscillation end of the frequency generation circuit according to the first voltage. In addition, the invention also provides a memory storage device and a signal generation method.)

1. A spread spectrum frequency generator, comprising:

a frequency generation circuit;

an impedance component connected to an impedance terminal of the frequency generation circuit; and

a control circuit connected to the impedance component,

wherein the control circuit is used for providing a control signal to the impedance component to generate a first voltage at the impedance end, and

the frequency generation circuit is used for generating a spread spectrum frequency signal at an oscillation end of the frequency generation circuit according to the first voltage.

2. The spread spectrum frequency generator of claim 1 wherein the spread spectrum frequency generator does not comprise a phase locked loop circuit.

3. The spread spectrum frequency generator of claim 1 wherein the impedance value of the impedance component affects the range of frequency variation of the spread spectrum frequency signal.

4. The spread spectrum frequency generator of claim 1, wherein a voltage value of the control signal affects a frequency variation amount of the spread spectrum frequency signal.

5. The spread spectrum frequency generator of claim 1 wherein the frequency generation circuit comprises:

a voltage divider circuit at the impedance terminal and connected to the impedance component; and

an oscillation circuit located at the oscillation end and connected to the voltage division circuit,

wherein the voltage divider circuit is configured to generate the first voltage in response to the control signal, and

the oscillating circuit is used for comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

6. The spread spectrum frequency generator of claim 5 wherein the oscillating circuit comprises:

a comparator connected to the voltage dividing circuit and used for comparing the first voltage with the second voltage and generating a comparison signal; and

an oscillator connected to the comparator and used for generating the spread spectrum frequency signal according to the comparison signal.

7. The spread spectrum frequency generator of claim 6 wherein the oscillator is further used to adjust the frequency of the spread spectrum frequency signal according to the comparison signal.

8. The spread spectrum frequency generator of claim 5 wherein the frequency generation circuit further comprises:

and the charging and discharging circuit is connected to the oscillating circuit and is used for providing the second voltage according to the spread spectrum frequency signal.

9. The spread spectrum frequency generator of claim 1 wherein the voltage of the control signal oscillates within a default voltage range.

10. The spread spectrum frequency generator of claim 9 wherein the control circuit comprises:

a charge and discharge circuit;

a control logic connected to the charge and discharge circuit; and

a comparison circuit connected to the control logic,

wherein the comparison circuit is configured to compare the control signal with a plurality of reference signals, and

and the control logic controls the charge and discharge circuit to generate the control signal according to the comparison result.

11. A memory storage device, comprising:

a connection interface unit for connecting to a host system;

a rewritable non-volatile memory module; and

a memory control circuit unit connected to the connection interface unit and the rewritable nonvolatile memory module,

wherein the memory control circuit unit includes a spread spectrum frequency generator,

the spread spectrum frequency generator is used for providing a control signal to the impedance component so as to generate a first voltage at an impedance end of the spread spectrum frequency generator,

the impedance component is connected to the impedance terminal, and

the spread spectrum frequency generator is further used for generating a spread spectrum frequency signal at an oscillation end of the spread spectrum frequency generator according to the first voltage.

12. The memory storage device of claim 11, wherein the spread spectrum frequency generator does not include a phase locked loop circuit.

13. The memory storage device of claim 11, wherein an impedance value of the impedance component affects a frequency variation range of the spread spectrum frequency signal.

14. The memory storage device of claim 11, wherein a voltage value of the control signal affects a frequency variation of the spread spectrum frequency signal.

15. The memory storage device of claim 11, wherein the spread spectrum frequency generator comprises:

a voltage divider circuit at the impedance terminal and connected to the impedance component; and

an oscillation circuit located at the oscillation end and connected to the voltage division circuit,

wherein the voltage divider circuit is configured to generate the first voltage in response to the control signal, and

the oscillating circuit is used for comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

16. The memory storage device of claim 15, wherein the oscillation circuit comprises:

a comparator connected to the voltage dividing circuit and used for comparing the first voltage with the second voltage and generating a comparison signal; and

an oscillator connected to the comparator and used for generating the spread spectrum frequency signal according to the comparison signal.

17. The memory storage device of claim 16, wherein the oscillator is further configured to adjust a frequency of the spread spectrum frequency signal according to the comparison signal.

18. The memory storage device of claim 15, wherein the spread spectrum frequency generator further comprises:

and the charging and discharging circuit is connected to the oscillating circuit and is used for providing the second voltage according to the spread spectrum frequency signal.

19. The memory storage device of claim 11, wherein a voltage of the control signal oscillates within a default voltage range.

20. The memory storage device of claim 19, wherein the spread spectrum frequency generator comprises:

a charge and discharge circuit;

a control logic connected to the charge and discharge circuit; and

a comparison circuit connected to the control logic,

wherein the comparison circuit is configured to compare the control signal with a plurality of reference signals, and

and the control logic controls the charge and discharge circuit to generate the control signal according to the comparison result.

21. A signal generation method for a memory storage device, the signal generation method comprising:

providing a control signal to an impedance component to generate a first voltage at an impedance terminal of a spread spectrum frequency generator in the memory storage device, wherein the impedance component is connected to the impedance terminal; and

and generating a spread spectrum frequency signal at an oscillation end of the spread spectrum frequency generator according to the first voltage.

22. The signal generating method of claim 21, wherein the spread spectrum frequency generator does not include a phase locked loop circuit.

23. The signal generating method according to claim 21, wherein an impedance value of the impedance component affects a frequency variation range of the spread spectrum frequency signal.

24. The signal generating method according to claim 21, wherein a voltage value of the control signal affects a frequency change amount of the spread spectrum frequency signal.

25. The signal generating method according to claim 21, wherein the step of generating the spread spectrum frequency signal at the oscillating end of the spread spectrum frequency generator according to the first voltage comprises:

generating the first voltage in response to the control signal; and

comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

26. The signal generating method according to claim 25, wherein the step of comparing the first voltage with the second voltage of the oscillating terminal to generate the spread spectrum frequency signal comprises:

comparing the first voltage with the second voltage and generating a comparison signal; and

and generating the spread spectrum frequency signal according to the comparison signal.

27. The signal generating method of claim 26, further comprising:

and adjusting the frequency of the spread spectrum frequency signal according to the comparison signal.

28. The signal generating method of claim 25, further comprising:

the second voltage is provided according to the spread spectrum frequency signal.

29. The signal generation method of claim 21, wherein a voltage of the control signal oscillates within a default voltage range.

30. The signal generating method of claim 29, further comprising:

comparing the control signal to a plurality of reference signals; and

and controlling the charging and discharging circuit to generate the control signal according to the comparison result.

Technical Field

The present invention relates to signal processing technologies, and in particular, to a spread spectrum frequency generator, a memory storage device, and a signal generating method.

Background

Digital cameras, mobile phones and MP3 players have grown rapidly over the years, resulting in a rapid increase in consumer demand for storage media. Since a rewritable non-volatile memory module (e.g., flash memory) has the characteristics of non-volatility, power saving, small volume, and no mechanical structure, it is very suitable for being built in the portable multimedia devices.

Spread Spectrum (SS) frequencies have low Electromagnetic Interference (EMI) characteristics. Therefore, the spread spectrum frequency can be applied to electronic devices such as memory storage devices. A conventional spread spectrum frequency generator is built in or externally connected to a Phase-locked loop (PLL) circuit, so as to generate a spread spectrum frequency signal by spreading the frequency signal through a specific circuit (e.g., a frequency divider) in the PLL circuit. However, as the size of the electronic device is further reduced, the spread spectrum frequency generator of the internal or external phase-locked loop circuit occupies more space in the circuit layout and the circuit design is more complicated.

Disclosure of Invention

The invention provides a spread spectrum frequency generator, a memory storage device and a signal generating method, which can simplify the design of the spread spectrum frequency generator and/or improve the efficiency of the spread spectrum frequency generator.

An exemplary embodiment of the present invention provides a spread spectrum frequency generator, which includes a frequency generating circuit, an impedance component and a control circuit. The impedance component is connected to an impedance terminal of the frequency generation circuit. The control circuit is connected to the impedance component. The control circuit is used for providing a control signal to the impedance component so as to generate a first voltage at the impedance end. The frequency generation circuit is used for generating a spread spectrum frequency signal at an oscillation end of the frequency generation circuit according to the first voltage.

In an exemplary embodiment of the invention, the frequency generating circuit includes a voltage dividing circuit and an oscillating circuit. The voltage divider circuit is located at the impedance terminal and connected to the impedance component. The oscillating circuit is located at the oscillating end and is connected to the voltage dividing circuit. The voltage divider circuit is used for responding to the control signal to generate the first voltage. The oscillating circuit is used for comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

In an exemplary embodiment of the invention, the frequency generating circuit further includes a charging and discharging circuit. The charging and discharging circuit is connected to the oscillating circuit and is used for providing the second voltage according to the spread spectrum frequency signal.

In an exemplary embodiment of the invention, the control circuit includes a charging/discharging circuit, a control logic and a comparison circuit. The control logic is connected to the charge and discharge circuit. The comparison circuit is connected to the control logic. The comparison circuit is used for comparing the control signal with a plurality of reference signals. And the control logic controls the charge and discharge circuit to generate the control signal according to the comparison result.

An exemplary embodiment of the present invention further provides a memory storage device, which includes a connection interface unit, a rewritable nonvolatile memory module and a memory control circuit unit. The connection interface unit is used for connecting to a host system. The memory control circuit unit is connected to the connection interface unit and the rewritable nonvolatile memory module. The memory control circuit unit includes a spread spectrum frequency generator. The spread spectrum frequency generator is used for providing a control signal to the impedance component so as to generate a first voltage at an impedance end of the spread spectrum frequency generator. The impedance component is connected to the impedance terminal. The spread spectrum frequency generator is further used for generating a spread spectrum frequency signal at an oscillation end of the spread spectrum frequency generator according to the first voltage.

In an exemplary embodiment of the invention, the spread spectrum frequency generator includes a voltage divider circuit and an oscillator circuit. The voltage divider circuit is located at the impedance terminal and connected to the impedance component. The oscillating circuit is located at the oscillating end and is connected to the voltage dividing circuit. The voltage divider circuit is used for responding to the control signal to generate the first voltage. The oscillating circuit is used for comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

In an exemplary embodiment of the present invention, the oscillation circuit includes a comparator and an oscillator. The comparator is connected to the voltage dividing circuit and is used for comparing the first voltage with the second voltage and generating a comparison signal. The oscillator is connected to the comparator and used for generating the spread spectrum frequency signal according to the comparison signal.

In an exemplary embodiment of the invention, the oscillator is further configured to adjust a frequency of the spread spectrum frequency signal according to the comparison signal.

In an exemplary embodiment of the invention, the spread spectrum frequency generator further includes a charge/discharge circuit. The charging and discharging circuit is connected to the oscillating circuit and is used for providing the second voltage according to the spread spectrum frequency signal.

In an exemplary embodiment of the invention, the spread spectrum frequency generator includes a charging and discharging circuit, a control logic and a comparison circuit. The control logic is connected to the charge and discharge circuit. The comparison circuit is connected to the control logic. The comparison circuit is used for comparing the control signal with a plurality of reference signals. And the control logic controls the charge and discharge circuit to generate the control signal according to the comparison result.

An exemplary embodiment of the present invention further provides a signal generating method for a memory storage device. The signal generation method comprises the following steps: providing a control signal to an impedance component to generate a first voltage at an impedance terminal of a spread spectrum frequency generator in the memory storage device, wherein the impedance component is connected to the impedance terminal; and generating a spread spectrum frequency signal at the oscillation end of the spread spectrum frequency generator according to the first voltage.

In an exemplary embodiment of the present invention, the spread spectrum frequency generator does not include a phase locked loop circuit.

In an exemplary embodiment of the invention, the impedance value of the impedance component affects a frequency variation range of the spread spectrum frequency signal.

In an exemplary embodiment of the invention, the voltage value of the control signal affects a frequency variation of the spread spectrum frequency signal.

In an exemplary embodiment of the invention, the step of generating the spread spectrum frequency signal at the oscillation end of the spread spectrum frequency generator according to the first voltage includes: generating the first voltage in response to the control signal; and comparing the first voltage with a second voltage of the oscillating end to generate the spread spectrum frequency signal.

In an exemplary embodiment of the present invention, the step of comparing the first voltage with the second voltage of the oscillating terminal to generate the spread spectrum frequency signal includes: comparing the first voltage with the second voltage and generating a comparison signal; and generating the spread spectrum frequency signal according to the comparison signal.

In an exemplary embodiment of the invention, the signal generating method further includes: and adjusting the frequency of the spread spectrum frequency signal according to the comparison signal.

In an exemplary embodiment of the invention, the signal generating method further includes: the second voltage is provided according to the spread spectrum frequency signal.

In an exemplary embodiment of the present invention, the voltage of the control signal oscillates within a default voltage range.

In an exemplary embodiment of the invention, the signal generating method further includes: comparing the control signal to a plurality of reference signals; and controlling the charging and discharging circuit to generate the control signal according to the comparison result.

Based on the above, the spread spectrum frequency generator comprises an impedance component connected to the impedance terminal of the spread spectrum frequency generator. After receiving the control signal from the control circuit, the impedance component can generate a first voltage at the impedance end of the spread spectrum frequency generator. The frequency generating circuit can generate a spread spectrum frequency signal at the oscillating end according to the first voltage.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic diagram of a spread spectrum frequency generator according to an exemplary embodiment of the invention.

Fig. 2 is a diagram illustrating waveforms of control signals according to an exemplary embodiment of the present invention.

Fig. 3 is a schematic diagram illustrating a frequency variation of a spread spectrum frequency signal according to an exemplary embodiment of the invention.

Fig. 4 is a schematic diagram of a control circuit according to an exemplary embodiment of the present invention.

Fig. 5 is a schematic diagram of a spread spectrum frequency generator according to an exemplary embodiment of the invention.

FIG. 6 is a diagram illustrating a memory storage device according to an exemplary embodiment of the invention.

Fig. 7 is a flowchart illustrating a signal generating method according to an exemplary embodiment of the present invention.

Description of reference numerals:

10: a spread spectrum frequency generator;

11: a frequency generation circuit;

12: an impedance component;

13: a control circuit;

110: an impedance terminal;

120: an oscillating end;

112: a voltage dividing circuit;

122: an oscillation circuit;

114. 124, 411, 412: a current source;

131. 431 and 432: a comparator;

132: an oscillator;

133. 41: a charge and discharge circuit;

1331. 1332, 413, 414: a switch assembly;

CS: a control signal;

v0, V1, V2: a voltage;

CK: a spread spectrum frequency signal;

r1, R2, RC: a resistance component;

415. 51: a reversing component;

42: a control logic;

43: a comparison circuit;

401: a buffer assembly;

CS': a signal;

60: a memory storage device;

61: a connection interface unit;

62: a memory control circuit unit;

63: a rewritable non-volatile memory module;

s701: providing a control signal to an impedance component of a spread spectrum frequency generator to generate a first voltage at an impedance end of the spread spectrum frequency generator;

s702: generating a spread spectrum frequency signal at an oscillation end of the spread spectrum frequency generator according to the first voltage.

Detailed Description

In the following, a number of embodiments are presented to illustrate the invention, however, the invention is not limited to the illustrated embodiments. Suitable combinations between the embodiments are also allowed. The term "coupled" as used throughout this specification, including the claims, may refer to any direct or indirect coupling means. For example, if a first device couples to a second device, that connection should be interpreted as either being a direct connection, or a indirect connection via other devices and some means of connection. Furthermore, the term "signal" may refer to at least one current, voltage, charge, temperature, data, or any other signal or signals.

Fig. 1 is a schematic diagram of a spread spectrum frequency generator according to an exemplary embodiment of the invention. Referring to fig. 1, a spread spectrum frequency generator 10 is used to generate a spread spectrum frequency signal CK. For example, the frequency of the spread spectrum frequency signal CK may continuously vary with time. The spread spectrum frequency generator 10 may be disposed in a memory storage device or other type of electronic device.

The spread spectrum frequency generator 10 includes a frequency generating circuit 11, an impedance component 12 and a control circuit 13. The impedance component 12 is connected between the control circuit 13 and the frequency generation circuit 11. More specifically, the frequency generating circuit 11 includes an impedance terminal 110 and an oscillation terminal 120. The impedance component 12 is (directly) connected to the impedance terminal 110 of the frequency generating circuit 11. For example, the impedance component 12 may include one or more resistive components RC (and/or reactive components) to provide the impedance value. The control circuit 13 provides a control signal CS to the impedance device 12 to generate a voltage (also referred to as a first voltage) V1 at the impedance terminal 110. The clock generation circuit 11 generates the spread spectrum clock signal CK at the oscillation terminal 120 according to the voltage V1.

In an exemplary embodiment, the spread spectrum frequency generator 10 may not include a Phase Locked Loop (PLL) circuit. Therefore, the spread spectrum frequency signal CK output may not be processed by a PLL circuit or the like correction circuit inside the spread spectrum frequency generator 10. Compared to the conventional spread spectrum frequency generator including the PLL circuit, in an exemplary embodiment, the spread spectrum frequency generator 10 without the PLL circuit occupies a smaller circuit layout area, has a lower complexity of circuit design, and/or consumes less power during operation.

In an exemplary embodiment, the control signal CS is an oscillating signal or a periodic signal such as a triangular wave or a sine wave. In an exemplary embodiment, the voltage value of the control signal CS can affect the frequency variation of the spread spectrum clock signal CK. For example, the frequency variation of the spread spectrum frequency signal CK may be different at different time points, so that the spread spectrum frequency signal CK may have different frequencies.

In an exemplary embodiment, the impedance value of the impedance component 12 can affect the frequency variation range of the spread spectrum frequency signal CK. That is, the frequency of the spread spectrum clock signal CK can be varied within a default frequency variation range.

Fig. 2 is a diagram illustrating waveforms of control signals according to an exemplary embodiment of the present invention.

Fig. 3 is a schematic diagram illustrating a frequency variation of a spread spectrum frequency signal according to an exemplary embodiment of the invention.

Referring to fig. 2 and fig. 3, taking a triangular wave as an example, the voltage value of the control signal CS may oscillate within a voltage range defined by the upper limit voltage VA and the lower limit voltage VB at different time points. The frequency of the spread spectrum frequency signal CK may vary within a frequency range defined by the upper limit frequency fA and the lower limit frequency fB, corresponding to the voltage variation of the control signal CS. For example, the frequency difference between the upper limit frequency fA and the lower limit frequency fB may be denoted df. For example, at the time point t (i), in response to the voltage value of the control signal CS being v (i), the frequency of the spread spectrum clock signal CK may be f (i).

In an exemplary embodiment, the impedance value of the impedance element 12 may be used to control the frequency difference df. For example, the impedance value of the impedance component 12 may be inversely related to the frequency difference df. That is, if the impedance value of the impedance component 12 is smaller, the frequency of the spread spectrum frequency signal CK can be changed within a larger frequency change range.

In an exemplary embodiment, the frequency generating circuit 11 may include a voltage dividing circuit 112, an oscillating circuit 122, a current source 114 and a current source 124. The voltage divider circuit 112 may be located at the impedance terminal 110 and connected to the impedance component 12. The oscillating circuit 122 may be located at the oscillating end 120 and connected to the voltage dividing circuit 112. Via the impedance component 12, the voltage divider circuit 112 may generate the voltage V1 in response to the control signal SC. The oscillating circuit 122 can receive the voltage V1 and the voltage (also referred to as a second voltage) V2 and compare the voltage V1 and the voltage V2 to generate the spread spectrum clock signal CK. It is noted that the voltage V1 is generated at the impedance end 110, and the voltage V2 is generated at the oscillation end 120, as shown in FIG. 1.

In an exemplary embodiment, the voltage divider circuit 112 may perform a voltage dividing operation on the control signal CS flowing through the impedance device 12 to generate voltages (also referred to as initial voltages) V0 and V1. For example, the voltage divider circuit 112 may include impedance devices R1 and R2. The impedance components R1 and R2 may provide the same or similar impedance values. The voltage V1 may be generated at the output of the voltage divider circuit 112.

In an exemplary embodiment, the oscillating circuit 122 may include a comparator 131, an oscillator 132, and a charging/discharging circuit 133. The comparator 131 is connected to the voltage divider 112, the oscillator 132 and the charge/discharge circuit 133. The comparator 131 can receive the voltages V1 and V2. The comparator 131 can compare the voltages V1 and V2 and generate a comparison signal. This comparison signal may reflect the difference between voltages V1 and V2. The oscillator 132 may generate a spread spectrum clock signal CK according to the comparison signal from the comparator 131. For example, the oscillator 132 may include a voltage controlled oscillator or other type of oscillator.

In an exemplary embodiment, the oscillator 132 may adjust the frequency of the spread spectrum clock signal CK according to the comparison signal from the comparator 131. For example, the spread spectrum clock CK may have different frequencies according to different voltage differences between the voltages V1 and V2.

In an exemplary embodiment, the charging/discharging circuit 133 provides the voltage V2 to the comparator 131 according to the spread spectrum clock signal CK. For example, the charging/discharging circuit 133 may include a switch device 1331, a switch device 1332 and a capacitor C. The switch 1331 and the switch 1332 can be turned on or off according to the frequency of the spread spectrum clock signal CK to charge and discharge the capacitor C, respectively.

In an exemplary embodiment, the control circuit 13 may include a periodic signal generator or an oscillation signal generator to generate the control signal CS including a triangular wave or a sine wave. Taking a triangular wave as an example, the waveform of the control signal CS can be as shown in fig. 2.

Fig. 4 is a schematic diagram of a control circuit according to an exemplary embodiment of the present invention. Please refer to

Referring to fig. 4, in an exemplary embodiment, the control circuit 13 includes a charging/discharging circuit 41, a control logic 42 and a comparing circuit 43. The control logic 42 is connected to the charge/discharge circuit 41 and the comparison circuit 43. The control logic 42 may control the charging and discharging circuit 41 to generate the signal CS' according to the comparison result of the comparing circuit 43. Comparison circuit 43 may compare signal CS' with signals Vb and Vbb (also referred to as reference signals), respectively, and output the comparison results to control logic 42.

In an exemplary embodiment, the charging/discharging circuit 41 may include a current source 411, a current source 412, a switch element 413, a switch element 414 and an inverter element 415. According to the control voltage from the control logic 42, the inverted control voltage of the inverted component 415 may be used to control the switch component 413 to turn on or off the current source 411, and the non-inverted control voltage may be used to control the switch component 414 to turn on or off the current source 412. Thus, the charge/discharge circuit 41 can output the signal CS'.

In an example embodiment, the comparison circuit 43 may include comparators 431 and 432. Comparator 431 is configured to compare signals Vb and CS' and generate an output according to the comparison result. Comparator 432 may be configured to compare signals Vbb and CS' and generate an output according to the comparison result. In an example embodiment, the control logic 42 may control the voltage of the signal CS 'to be less than the voltage of the signal Vb according to the comparison result of the signals Vb and CS'. For example, the voltage of the signal Vb may be the same as the upper limit voltage VA of fig. 2. In an example embodiment, the control logic 42 may control the voltage of the signal CS 'to be greater than the voltage of the signal Vbb according to the comparison result of the signals Vbb and CS'. For example, the voltage of the signal Vbb may be the same as the lower limit voltage VB of fig. 2. In an exemplary embodiment, the voltage value of the signal CS 'may oscillate within a default voltage range according to the comparison result of the signal CS' with Vb and Vbb, respectively, as shown in fig. 2.

In an exemplary embodiment, the comparators 431 and 432 may be Schmitt triggers (Schmitt triggers) or other type of comparators with similar functions, respectively. In an example embodiment, the control circuit 13 may further include a buffer element 401. The signal CS' may pass through the buffer component 401 to become the control signal CS.

Fig. 5 is a schematic diagram of a spread spectrum frequency generator according to an exemplary embodiment of the invention. Referring to fig. 5, compared to the exemplary embodiment of fig. 1, in the spread spectrum frequency generator 50, the oscillator 132 of the spread spectrum frequency generator 10 is replaced by the inverting component 51. In the present exemplary embodiment, the output of the comparator 131 can be used as the spread spectrum clock signal CK. The non-inverted spread spectrum frequency signal CK may be used to control the switch component 1331, and the inverted spread spectrum frequency signal CK may be used to control the switch component 1332 to generate the voltage V2. In addition, components with the same reference numerals in fig. 5 may refer to the description of the exemplary embodiment of fig. 1, and are not repeated herein.

In an exemplary embodiment, the spreading frequency generator 10 of fig. 1 or the spreading frequency generator 50 of fig. 5 may be disposed in a memory storage device or a memory control circuit unit to operate together with the memory storage device or the memory control circuit unit. However, in an exemplary embodiment, the spreading frequency generator 10 of fig. 1 or the spreading frequency generator 50 of fig. 5 may be disposed in other types of electronic devices.

FIG. 6 is a diagram illustrating a memory storage device according to an exemplary embodiment of the invention. Referring to fig. 6, the memory storage device 60 may be used with a host system that can write data to the memory storage device 60 or read data from the memory storage device 60. For example, the host system may be any system that substantially cooperates with the memory storage device 60 to store data, such as a desktop computer, a notebook computer, a digital camera, a video camera, a communication device, an audio player, a video player, a tablet computer, or the like.

The memory storage device 60 includes a connection interface unit 61, a memory control circuit unit 62, and a rewritable nonvolatile memory module 63. The connection interface unit 61 is used to connect the memory storage device 60 to a host system. In an exemplary embodiment, connection interface unit 61 is compliant with the Serial Advanced Technology Attachment (SATA) standard. However, it should be understood that the present invention is not limited thereto, and the connection interface unit 61 may also conform to Parallel Advanced Technology Attachment (PATA) standard, Peripheral Component Interconnect Express (PCI Express) standard, Universal Serial Bus (USB) standard or other suitable standards. The connection interface unit 61 may be packaged in one chip with the memory control circuit unit 62, or the connection interface unit 61 may be disposed outside the chip including the memory control circuit unit 62.

The memory control circuit unit 62 is used for performing operations such as writing, reading and deleting data in the rewritable nonvolatile memory module 63 according to instructions of the host system. The rewritable nonvolatile memory module 63 is connected to the memory control circuit unit 62 and is used for storing data written by the host system. The rewritable nonvolatile memory module 63 may be a Single Level Cell (SLC) NAND-type flash memory module (i.e., a flash memory module that can store 1 bit in one memory Cell), a Multi-Level Cell (MLC) NAND-type flash memory module (i.e., a flash memory module that can store 2 bits in one memory Cell), a Triple Level Cell (TLC) NAND-type flash memory module (i.e., a flash memory module that can store 3 bits in one memory Cell), a Quad Level Cell (QLC) NAND-type flash memory module (i.e., a flash memory module that can store 4 bits in one memory Cell), other flash memory modules, or other memory modules having the same characteristics.

Each memory cell in the rewritable nonvolatile memory module 63 stores one or more bits by a change in voltage (hereinafter also referred to as a threshold voltage). Specifically, each memory cell has a charge trapping layer between the control gate and the channel. By applying a write voltage to the control gate, the amount of electrons in the charge trapping layer can be varied, thereby varying the threshold voltage of the memory cell. This operation of changing the threshold voltage of the memory cell is also referred to as "writing data to the memory cell" or "programming" the memory cell. As the threshold voltage changes, each memory cell in the rewritable nonvolatile memory module 63 has a plurality of storage states. The read voltage is applied to determine which storage state a cell belongs to, thereby obtaining one or more bits stored in the cell.

In the exemplary embodiment, the memory cells of the rewritable nonvolatile memory module 63 may constitute a plurality of physical programming units, and the physical programming units may constitute a plurality of physical erasing units. Specifically, the memory cells of the same word line may constitute one or more physical programming cells. If each memory cell can store more than 2 bits, the on-line physical program cells of the same word can be classified into at least a lower physical program cell and an upper physical program cell. For example, the Least Significant Bit (LSB) of the memory cell belongs to the lower physical program cell, and the Most Significant Bit (MSB) of the memory cell belongs to the upper physical program cell. Generally, in the MLC NAND flash memory, the writing speed of the lower physical program cell is faster than that of the upper physical program cell, and/or the reliability of the lower physical program cell is higher than that of the upper physical program cell.

In the present exemplary embodiment, the physical program cell is a programmed minimum cell. That is, the physical programming unit is the minimum unit for writing data. For example, the physical programming unit can be a physical page (page) or a physical fan (sector). If the physical programming units are physical pages, the physical programming units may include a data bit region and a redundancy (redundancy) bit region. The data bit region includes a plurality of physical sectors for storing user data, and the redundant bit region stores system data (e.g., management data such as error correction codes). In the present exemplary embodiment, the data bit region includes 32 physical sectors, and the size of one physical sector is 512 bytes (B). However, in other exemplary embodiments, 8, 16 or more or less physical fans may be included in the data bit region, and the size of each physical fan may be larger or smaller. On the other hand, the entity deletion unit is the minimum unit of deletion. That is, each physical delete unit contains one of the minimum number of memory cells that are deleted. For example, the physical deletion unit is a physical block (block).

In an example embodiment, the rewritable nonvolatile memory module 63 of fig. 6 is also referred to as a flash memory module. In an example embodiment, the memory control circuit unit 62 of fig. 6 is also referred to as a flash controller for controlling a flash memory module. In an exemplary embodiment, the spreading frequency generator 10 of fig. 1 or 50 of fig. 5 can be disposed in the connection interface unit 61, the memory control circuit unit 62 or the rewritable nonvolatile memory module 63 of fig. 6 to provide a spreading frequency signal CK required by the device operation.

It should be noted that the circuit structures shown in fig. 1, fig. 4 and fig. 5 are only examples and are not intended to limit the present invention. In another exemplary embodiment, the connection relationship among the electronic components in the circuit structures shown in fig. 1, 4 and 5 can be adjusted according to practical requirements. In another exemplary embodiment, the electronic components in the circuit structures shown in fig. 1, 4 and 5 may be replaced by electronic components having the same or similar functions. In addition, the circuit structures shown in fig. 1, fig. 4 and fig. 5 may also include other types of electronic components to provide other additional functions, and the invention is not limited thereto.

Fig. 7 is a flowchart illustrating a signal generating method according to an exemplary embodiment of the present invention. Referring to fig. 7, in step S701, a control signal is provided to an impedance component of a spread spectrum frequency generator to generate a first voltage at an impedance terminal of the spread spectrum frequency generator. In step S702, a spread spectrum frequency signal is generated at the oscillating end of the spread spectrum frequency generator according to the first voltage.

However, the steps in fig. 7 have been described in detail above, and are not described again here. It is to be noted that, the steps in fig. 7 can be implemented as a plurality of program codes or circuits, and the invention is not limited thereto. In addition, the method of fig. 7 may be used with the above exemplary embodiments, or may be used alone, and the invention is not limited thereto.

In summary, the spread spectrum frequency provided by the exemplary embodiments of the invention does not include the PLL circuit and can generate a stable spread spectrum frequency signal. Compared to the conventional spread spectrum frequency generator including the PLL circuit, in an exemplary embodiment, the spread spectrum frequency generator without the PLL circuit occupies a smaller circuit layout area, has a lower complexity of circuit design, and/or consumes less power during operation.

Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto, and various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.