JP4471901B2 - Random number generator - Google Patents

Description

  The present invention relates to a random number generation device, and more particularly to a random number generation device that generates a random number based on the output of a circuit when the output of the circuit is unstable.

  In the information security field, the use of random numbers is indispensable, and in recent years, it has uniformity (there is no difference in the probability value and appearance rate of random numbers), and the regularity of random numbers appearance, the correlation before and after, and the period. There is an increasing demand for high-performance random number generators that generate natural random numbers (genuine random numbers) that do not have such characteristics.

  For example, Patent Document 1 discloses the following random number generator. That is, the cascaded Muller C gates 1 and 2 detect the falling point of the first square wave F after the rising point of the second square wave S, and the cascaded Muller C gates 3 and 4 are connected. Detects the rising point of the first square wave F after the rising point of the second square wave S, and if the value of the first square wave F is 1 at the rising point of the second square wave S, NAND When the gate 5 outputs 0 as a random number and the value of the first square wave F is 0 at the time of rising of the second square wave S, the NAND gate 6 outputs 0 as a random number.

Patent Document 2 discloses the following random number generator. That is, a plurality of delay circuits connected in a loop, a pulse generation circuit that generates a pulse signal having a pulse width shorter than the total delay time of the plurality of delay circuits in a loop formed by the plurality of delay circuits, and a plurality of A counter is connected to an output node of a delay circuit in the delay circuit, counts the number of times the pulse signal has passed through the output node, and outputs genuine random number data based on the count value.
JP 2003-150372 A JP 2005-18251 A

  By the way, since the random number generation device described in Patent Document 1 is configured to generate a random number according to the relationship between two input signals, there is a problem in that randomness deteriorates when an appropriate input signal cannot be generated. there were.

  In addition, the random number generation device described in Patent Document 2 is configured to generate a random number based on a circuit output in a metastable state in which the circuit output becomes unstable due to an indefinite operation of the circuit. If the count value before the extinction, that is, before the pulse signal passing through the output node disappears, is output as a genuine random number data, random numbers that do not depend on the life of the metastable are generated, so the randomness may deteriorate. There was a problem that there was.

  Therefore, an object of the present invention is to provide a random number generator capable of improving randomness.

  In order to solve the above-described problem, a random number generation device according to an aspect of the present invention includes a random number generation unit that generates random number data based on an output of a circuit in a metastable in which the output of the circuit is unstable, and a random number A random number storage unit that stores data; and a control unit that controls the random number storage unit to store random number data output from the random number generation unit after the metastable disappears.

  A random number generator according to still another aspect of the present invention includes a random number generation unit that generates random number data based on an output of a circuit in a metastable in which the output of the circuit is unstable, and a random number that stores the random number data A storage unit, a detector that detects the disappearance of the metastable, and if the detector detects the disappearance of the metastable within a predetermined time from the occurrence of the metastable, or after the predetermined time has elapsed When the detector does not detect the disappearance of the metastable, the detector includes a control unit that performs control to store the random number data output from the random number generation unit in the random number storage unit after a predetermined time has elapsed.

  According to the present invention, randomness can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a random number generation device according to the first embodiment of the present invention. Referring to the figure, a random number generation device includes a random number generation unit 1, an M sequence generation unit (pseudo random number generation unit) 2, an EXOR (exclusive OR) gate 3, a random number storage unit 4, and a control signal. And a generation unit 5. The random number generation unit 1 includes a ring oscillator 11 (random number oscillator) and a binarization unit 12.

  The random number generation unit 1 generates random number data based on the output of the ring oscillator 11 when the metastable is generated in the ring oscillator 11.

  The M sequence generation unit 2 generates a known M sequence (longest code sequence). The M-sequence is uniform pseudo-random data, that is, pseudo-random data having regularity with both occurrence probability of “0” and “1” being 50%. The random number generation unit 1 and the M sequence generation unit 2 operate asynchronously.

  The EXOR gate 3 outputs an exclusive OR of the random number data received from the random number generation unit 1 and the pseudo random number data received from the M sequence generation unit 2. The random number data generated by the random number generation unit 1 is not guaranteed to be uniform, but the pseudo-random number data generated by the M-sequence generation unit 2 is guaranteed to be uniform. Random number data with is output.

  The random number storage unit 4 stores the random number data received from the EXOR gate 3 and outputs it as a random number. More specifically, the random number storage unit 4 includes a plurality of registers for storing a plurality of bits of random number data. The random number storage unit 4 receives a read signal (not shown) output from an external circuit such as a CPU and outputs the random number data stored in each register as a random number to the CPU bus.

  The control signal generation unit 5 controls the random number generation unit 1, the M sequence generation unit 2, and the random number storage unit 4 to generate random numbers.

  FIG. 2 is a diagram illustrating the configuration of the ring oscillator 11 and the binarization unit 12. Referring to the figure, ring oscillator 11 includes inverters 21a-21e and NAND gates 22a-22c. The binarization unit 12 includes registers 23a to 23c and an EXOR gate 24.

  The ring oscillator 11 enters an oscillation state or a stable state according to the oscillation control signal received from the control signal generation unit 5. The binarization unit 12 counts the number of times the pulse signal has passed through each node in the loop of the ring oscillator 11, and outputs random number data based on the count value.

  More specifically, the circuit formed of NAND gates 22a to 22c and inverter 21a forms a loop composed of an odd number of inverters or an even number according to the oscillation control signal received from control signal generation unit 5. The loop consisting of the inverters is switched.

  In the ring oscillator 11, the connection point between the output of the inverter 21b and the input of the NAND gate 22b is a node N21, the connection point between the output of the NAND gate 22c and the input of the inverter 21c is a node N22, and the output of the inverter 21d and the inverter 21e. The connection point of the input is node N23.

  The nodes N21 to N23 are connected to clock input terminals of the registers 23a to 23c in the binarization unit 12, respectively.

  With such a configuration, when the oscillation control signal is at the H level, the output signal of the NAND gate 22b is at the H level. Therefore, from the loop composed of the inverters 21c to 21e and the NAND gates 22a and 22c, that is, from an odd number of inverters. A loop is formed. When the oscillation control signal is at the L level, the output signal of the NAND gate 22a is at the H level, so that a loop composed of the inverters 21b to 21e and the NAND gates 22b and 22c, that is, a loop composed of an even number of inverters is formed. . Therefore, when the oscillation control signal is at the L level, the logic level of the output signal of each inverter and each NAND gate is determined, so that the loop becomes stable, but when the oscillation control signal is at the H level, each inverter and each NAND gate. Since the output signal repeats H level and L level, the loop enters an oscillation state.

  The registers 23a to 23c are 1-bit counters to which an inverting output terminal and a data input terminal are connected. The registers 23a to 23c invert the output signal from the positive / inverted output terminal every time the rising edge of the signal input to the clock input terminal is detected.

  FIG. 3 is a time chart for explaining operations of the ring oscillator 11 and the binarization unit 12.

  Referring to the figure, the oscillation control signal output from control signal generator 5 is a pulse signal that rises to H level at time t0 and falls to L level after time T0 has elapsed. This time T0 (pulse width) is shorter than the delay time T1 of the loop of the ring oscillator 11.

  When the oscillation control signal changes from the L level to the H level, the loop changes from the stable state to the oscillation state as described above. In the oscillation state, the output signal of each inverter and each NAND gate repeats H level and L level, so that the pulse signal passes through each node in the loop of the ring oscillator 11. When the oscillation control signal changes from the H level to the L level, the loop ceases to be in the oscillation state, so that the pulse signal that has passed through each node in the oscillation state gradually becomes thin and eventually the pulse signal disappears and is in a stable state. It becomes. In this way, a state where a pulse signal thinner than the pulse signal in the oscillation state passes through the loop, that is, a state where the output of the ring oscillator 12 is unstable is a metastable. Here, the state in which the level of the pulse signal becomes small and the registers 23a to 23c cannot recognize the pulse signal as a clock, that is, the state in which the registers 23a to 23c cannot detect the rising edge or the falling edge of the pulse signal. It is the disappearance of the table.

  In the time chart shown in the figure, each register counts the number of pulses twice. That is, when the non-inverted output of each register is L level in the initial state, the non-inverted output of each register becomes H level at the first count and becomes L level at the second count. Then, the output signal of the EXOR gate 24 after the metastable disappears becomes L level.

  The life of the metastable is determined by the characteristics of each circuit in the loop of the ring oscillator 11, and the characteristics of each circuit vary depending on the manufacturing variation and the ambient temperature. Therefore, the life of the metastable cannot be controlled. The node where the table disappears, that is, the node through which the last pulse signal passes is indeterminate.

  For example, if the metastable disappears at the output node N22 after making two loops, the register corresponding to the output node N21 counts the number of pulses three times, and the registers corresponding to the output nodes N22 to N23 each have a pulse number of 2. Count once. That is, when the non-inverted output of each register is L level in the initial state, the non-inverted output of the register corresponding to the output node N21 after the metastable disappears becomes H level, and the registers corresponding to the output nodes N22 to N23 The non-inverted outputs of each become L level. Then, the output signal of the EXOR gate 24 after the metastable disappears becomes H level. Therefore, since the output signal of the binarization unit 12 at the time t1 after the elapse of a predetermined time from the time t0 (after the metastable disappears) depends on the life of the metastable, it is genuine random number data, that is, a random number having no regularity and high quality. It becomes data.

  As described above, the random number generation unit 1 in the random number generation device according to the present embodiment includes a loop composed of three (odd number) inverters and a loop composed of four (even number) inverters of the ring oscillator 11. By switching and binarizing the life of the metastable to “0” and “1”, genuine random number data is generated. Therefore, a compact, low power consumption and high performance random number generator can be realized.

FIG. 4 is a diagram illustrating a configuration of the M-sequence generation unit 2.
Referring to FIG. 2, M-sequence generation unit 2 includes n (n is a natural number of 3 or more) registers 91, a plurality of EXOR gates 92, an AND gate 93, and an OR gate 94.

  Each register 91 has its data input terminal connected to the non-inverted output terminal of the previous register 91, the M-sequence shift signal from the control signal generating unit 5 is input to the clock input terminal, and the inverted output terminal of the AND gate 93. Connected to input terminal. However, the first stage register 91 has a data input terminal connected to the output terminal of the OR gate 94.

  In each EXOR gate 92, one of the input terminals receives the non-inverted output of the corresponding register 91, and the other input terminal receives the output signal of the previous EXOR gate 92, and outputs an exclusive OR of these signals. However, one of the input terminals of the first-stage EXOR gate 92 receives the non-inverted output of the (n−2) -th stage register 91, and the other input terminal receives the output signal of the n-th stage EXOR gate 92.

  As described above, it is well known that pseudo-random numbers are generated by connecting a plurality of stages of registers 91 in series and feeding back the final output. The repetition period of the pseudo random number data output from the M-sequence generation unit 2 varies depending on the number and position of the EXOR gate 92, and the number and position of the EXOR gate 92 are determined so that the repetition period of the pseudo random number data is the longest. . In this case, pseudo random number data having a repetition period of (2n-1) is generated.

  The AND gate 93 outputs a logical product of the inverted outputs of the n registers 91. The OR gate 94 outputs a logical sum of the output signal of the final-stage EXOR gate 92 and the output signal of the AND gate 93. With such a configuration, it is possible to prevent the pseudo-random data output from the M-sequence generation unit 2 from being in the stable state at the L level because the non-inverted outputs of all the registers 91 are at the L level.

FIG. 5 is a diagram illustrating a configuration of the control signal generation unit 5.
Referring to the figure, control signal generation unit 5 includes a ring oscillator 101 (clock oscillator), registers 31a to 31b, and AND gates 32a to 32b.

FIG. 6 is a diagram illustrating a configuration of the ring oscillator 101.
Referring to the figure, ring oscillator 101 includes an AND gate 33 and inverters 34a to 34c.

  A loop composed of the AND gate 33 and the inverters 34a to 34c, that is, a loop composed of an odd number of inverters is formed. When the oscillation control signal is at L level, the output signal of the AND gate 33 is at L level, so that the output signal of the ring oscillator 101 is stabilized at H level. On the other hand, when the oscillation control signal is at the H level, the output signal of the AND gate 33 is at the H level. A control signal generation clock is output.

  Referring to FIG. 5 again, registers 31a to 31b sample and hold the data input to the data input terminal at the timing of the control signal generation clock received from ring oscillator 101, and output the held data. The non-inverting output terminal of the register 31a is connected to the data input terminal of the register 31b, and the inverting output terminal is connected to one of the input terminals of the AND gate 32a and one of the input terminals of the AND gate 32b. The non-inverting output terminal of the register 31b is connected to the other input terminal of the AND gate 32a, and the inverting output terminal is connected to the other input terminal of the AND gate 32b and the data input terminal of the register 31a.

  The output of the AND gate 32a becomes a random number storage signal, and the output of the AND gate 32b becomes an oscillation control signal and an M-sequence shift signal.

  Next, an operation when the control signal generation unit 5 controls each circuit to generate a random number will be described.

  FIG. 7 is a time chart of each signal in the random number generation device according to the first embodiment of the present invention.

  Control signal generator 5 changes the oscillation control signal and the M-sequence shift signal from L level to H level. When the oscillation control signal changes from the L level to the H level, the ring oscillator 11 in the random number generation unit 1 enters the oscillation state. When the M-sequence shift signal changes from the L level to the H level, each register in the M-sequence generation unit 2 performs a shift operation, and the output of the M-sequence generation unit 2, that is, the logic level of the pseudorandom data is, for example, from the L level to the H level. Change to level.

  Next, the control signal generation unit 5 changes the oscillation control signal and the M-sequence shift signal from the H level to the L level. When the oscillation control signal changes from the H level to the L level, the ring oscillator 11 is not oscillated and a metastable is generated in the ring oscillator 11.

  Then, the metastable disappears in the ring oscillator 11 and, for example, H level data is output from the random number generator 1 as the genuine random number data. The EXOR gate 3 receives H level data from the random number generation unit 1 and H level data from the M sequence generation unit 2 and outputs L level data as random number data.

  Next, the control signal generation unit 5 controls the random number storage unit 4 to store the random number data received from the EXOR gate 3 at the timing after the metastable disappears. In the figure, the control signal generator 5 changes the random number storage signal from the L level to the H level at the fourth clock of the control signal generation clock, which is the timing after the metastable disappears in the ring oscillator 11. When the random number storage signal changes from the L level to the H level, the random number storage unit 4 stores the L level random number data output from the EXOR gate 3.

  Here, in order to change the random number storage signal from the L level to the H level after the metastable disappears, it is necessary to increase the period of the control signal generation clock to some extent. As a method for increasing the period of the control signal generation clock, each inverter in the ring oscillator 101 included in the control signal generation unit 5 is a circuit having a large delay amount between input and output, or an inverter constituting a loop in the ring oscillator 101. It is conceivable to increase the number of terminals or connect an element having a large capacitance value to the output of the inverter.

  By the way, since the random number generation device described in Patent Document 1 is configured to generate a random number according to the relationship between two input signals, there is a problem in that randomness deteriorates when an appropriate input signal cannot be generated. there were.

  In addition, when the random number generation device described in Patent Document 2 outputs the count value before the metastable disappears as genuine random number data, random numbers that do not depend on the life of the metastable are generated, so that the randomness deteriorates. There was a problem that there was a case.

  However, in the random number generation device according to the first embodiment of the present invention, the control signal generation unit 5 controls the random number storage unit 4 so that the random number data received from the EXOR gate 3 is at the timing after the metastable disappears. Store. That is, a random number based on the life of the metastable is generated.

  Therefore, the random number generator according to the first embodiment of the present invention can improve randomness.

  In the random number generation device according to the first embodiment of the present invention, the frequency of the control signal generation clock generated by the ring oscillator 101 cannot be controlled from the outside of the random number generation device. Therefore, tamper resistance, that is, difficulty in analyzing the internal structure of the device and stored data can be improved.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
The present embodiment relates to a random number generation device in which the configurations of the ring oscillator 11 and the control signal generation unit 5 in the random number generation device according to the first embodiment are changed. That is, the random number generation device according to the present embodiment includes a ring oscillator 13 (random number oscillator) instead of the ring oscillator 11, and includes a control signal generation unit 15 instead of the control signal generation unit 5.

FIG. 8 is a diagram showing the configuration of the ring oscillator 13.
Referring to the figure, ring oscillator 13 includes NAND gates 41a to 41f. NAND gates 41a to 41f form a loop. This loop is equivalent to a loop composed of an even number of inverters, and is in a stable state regardless of whether the oscillation control signal is at L level or H level.

  In the ring oscillator 21, the connection point between the output of the NAND gate 41f and the input of the NAND gate 41a is the node N41, the connection point of the output of the NAND gate 41b and the input of the NAND gate 41c is the node N42, and the output of the NAND gate 41d The connection point of the inputs of the NAND gate 41e is the node N43.

  Nodes N41 to N43 are connected to clock input terminals of registers 23a to 23c in binarization unit 12, respectively.

  The configuration and operation of the ring oscillator 13 are the same as those of the ring oscillator shown in FIG. That is, the initial state of this loop is a stable state in which the potentials of nodes N41 to N43 are at the H level. In response to the rise of the oscillation control signal to the H level, the outputs of the NAND gates 41a to 41e are lowered to the L level, and then the potentials of the NAND gates 41a, 41c and 41e are set to the L level, the NAND gate 41b, The potentials of 41d and 41f make a transition to a stable state of H level. When the oscillation control signal is changed, metastable is sequentially generated in the nodes N41 to N43. The metastable waveform gradually decreases with time and disappears.

  Therefore, even if an oscillation control signal having a pulse width shorter than the delay time of the loop of the ring oscillator 21 is not generated, a metastable can be generated simply by raising the oscillation control signal from the L level to the H level. Therefore, the configuration of the random number generator can be simplified.

FIG. 9 is a diagram illustrating a configuration of the control signal generation unit 15.
Referring to FIG. 5, control signal generation unit 15 further includes an inverter 35 with respect to control signal generation unit 5 shown in FIG. The inverter 35 inverts the output of the AND gate 32b and outputs the inverted signal to the random number generator 1 as an oscillation control signal. Other configurations and operations are the same as those of the control signal generator 5 shown in FIG.

  Next, an operation when the control signal generation unit 15 controls each circuit to generate a random number will be described.

  FIG. 10 is a time chart of each signal in the random number generation device according to the second embodiment of the present invention.

  The control signal generation unit 15 changes the oscillation control signal from the H level to the L level. In this case, the ring oscillator 11 in the random number generation unit 1 is in a stable state, and the potential of each node is at the H level. Therefore, the output of the random number generation unit 1 is at the L level. Control signal generation unit 15 changes the M-sequence shift signal from the L level to the H level. When the M-sequence shift signal changes from the L level to the H level, each register in the M-sequence generation unit 2 performs a shift operation, and the output of the M-sequence generation unit 2, that is, the logical level of the pseudorandom data is changed from the L level to the H level, for example. Change.

  Next, the control signal generator 5 changes the oscillation control signal from the L level to the H level. When the oscillation control signal changes from L level to H level, a metastable is generated in the ring oscillator 13. Control signal generation unit 5 changes the M-sequence shift signal from the H level to the L level.

  Then, the metastable disappears in the ring oscillator 13, and H level data, for example, is output from the random number generator 1 as genuine random number data. The EXOR gate 3 receives H level data from the random number generation unit 1 and H level data from the M sequence generation unit 2 and outputs L level data as random number data.

  Next, the control signal generation unit 5 controls the random number storage unit 4 to store the random number data received from the EXOR gate 3 at the timing after the metastable disappears. In the figure, the control signal generator 5 changes the random number storage signal from the L level to the H level at the fourth clock of the control signal generation clock, which is the timing after the metastable disappears in the ring oscillator 13. When the random number storage signal changes from the L level to the H level, the random number storage unit 4 stores the L level random number data output from the EXOR gate 3.

  Therefore, since the random number generator according to the second embodiment of the present invention can generate a random number based on the lifetime of the metastable as in the random number generator according to the first embodiment, Can be improved. In addition, tamper resistance can be improved as in the random number generation device according to the first embodiment.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Third Embodiment>
The present embodiment relates to a random number generation device in which the configuration of the control signal generation unit 5 in the random number generation device according to the first embodiment is changed. That is, the random number generation device according to the present embodiment includes a control signal generation unit 25 instead of the control signal generation unit 5.

FIG. 11 is a diagram illustrating a configuration of the control signal generation unit 25.
Referring to FIG. 5, control signal generation unit 25 includes a frequency divider 51 instead of ring oscillator 101 with respect to control signal generation unit 5 shown in FIG. 5. The frequency divider 51 divides a system clock or an internal oscillation clock input to the random number generator from the outside, and outputs the divided clock to the registers 31a to 31b as a control signal generation clock. Other configurations and operations are the same as those of the control signal generator 5 shown in FIG.

  Therefore, since the random number generation device according to the present embodiment can generate a random number based on the lifetime of the metastable as with the random number generation device according to the first embodiment, the randomness can be improved. .

  Here, in the random number generation device according to the first embodiment, as described above, in order to increase the cycle of the control signal generation clock, a method such as increasing the number of inverters constituting the loop in the ring oscillator 101 is employed. Therefore, the circuit scale of the ring oscillator 101 becomes large. However, in the random number generation device according to the present embodiment, a ring oscillator that generates a clock is not necessary, and the frequency divider can be composed of several registers, for example, so that the circuit scale can be reduced.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fourth embodiment>
The present embodiment relates to a random number generation device in which the configuration of the control signal generation unit 5 in the random number generation device according to the first embodiment is changed. That is, the random number generation device according to the present embodiment includes a control signal generation unit 35 instead of the control signal generation unit 5.

FIG. 12 is a diagram illustrating a configuration of the control signal generation unit 35.
Referring to FIG. 5, control signal generation unit 25 includes registers 52a to 52c. Registers 52a to 52c hold data received from a CPU (Central Processing Unit) (not shown) via a CPU bus at the timing of a write signal similarly received from the CPU, and hold the held data respectively as an oscillation control signal, random number storage signal, and Output as an M-sequence shift signal. That is, the CPU controls the registers 52a to 52c to generate the same oscillation control signal, random number storage signal, and M-sequence shift signal as in FIG. Here, the CPU exists outside the random number generator.

  Next, an operation when the control signal generation unit 5 controls each circuit to generate a random number will be described.

  FIG. 13 is a time chart of each signal in the random number generation device according to the fourth embodiment of the present invention.

  In the figure, the MSB (Most Significant Bit) of CPU bus data corresponds to the register 52a, the second bit from the MSB corresponds to the register 52b, and the LSB (Least Significant Bit) corresponds to the register 52c.

  The CPU changes the CPU bus data in accordance with the timing of changing the logic levels of the oscillation control signal, random number storage signal, and M-sequence shift signal, and outputs a write signal to each register, as shown in FIG. Generating an oscillation control signal, a random number storage signal, and an M-sequence shift signal. Since other operations are the same as those in FIG. 7, the description will not be repeated here.

  Therefore, since the random number generation device according to the present embodiment can generate a random number based on the lifetime of the metastable as with the random number generation device according to the first embodiment, the randomness can be improved. .

  Furthermore, in the random number generation device according to the present embodiment, since the control signal generation unit 35 is configured by only three registers, the circuit scale is smaller than that of the random number generation device according to the first to third embodiments. can do.

  In the random number generation device according to the present embodiment, the control signal generation unit 25 includes the registers 52a to 52c. However, the present invention is not limited to this, and the control signal generation unit 25 includes the registers 52a to 52c. The CPU controls at least one of the oscillation control signal, the random number storage signal, and the M-sequence shift signal.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fifth embodiment>
The present embodiment relates to a random number generation device that detects the disappearance of the metastable and changes the configuration of the control signal generation unit 5 in the random number generation device according to the first embodiment.

FIG. 14 is a diagram showing a configuration of a random number generation device according to the fifth embodiment of the present invention.
Referring to the figure, the random number generator further includes a metastable disappearance detector 6 in addition to the random number generator according to the first embodiment, and generates a control signal instead of the control signal generator 5. The unit 45 is provided. The metastable disappearance detector 6 includes a register 61 and an AND gate 62.

  The output of the EXOR gate 3 is connected to the clock input terminal of the register 61, the fixed potential of H level is connected to the data input terminal, and the extinction detection reset from the control signal generator 45 is input to the reset terminal. The output of the register 61 is connected to one input terminal of the AND gate 62, and the gate control signal from the control signal generation unit 45 is input to the other. The AND gate 62 outputs the logical product of both input terminals to the control signal generation unit 45 as the disappearance detection result.

  Next, an operation when the random number generation device according to the present embodiment detects the disappearance of the metastable and generates a random number will be described.

  FIG. 15 is a time chart of each signal in the random number generation device according to the fifth embodiment of the present invention.

  Since the operation until the metastable is generated is the same as that of the random number generation device according to the first embodiment, description thereof will not be repeated here.

  After the metastable is generated in the ring oscillator 11, the control signal generation unit 45 changes the disappearance detection reset from the L level to the H level. When the extinction detection reset becomes H level, the register 61 is reset and the output of the register 61 becomes L level.

  Next, the control signal generation unit 45 changes the disappearance detection reset from the H level to the L level to release the reset state of the register 61. Then, the control signal generation unit 45 changes the gate control signal from the L level to the H level after the reset state of the register 61 is released, and receives the disappearance detection result output from the AND gate 62.

  Here, when the metastable has not disappeared, the random number data from the random number generation unit 1 repeats the H level and the L level. Further, the output from the M sequence generation unit 2 is stable at the H level or the L level. Therefore, the output from the EXOR gate 3 input to the clock input terminal of the register 61 repeats the H level and the L level, and the potential of the data input terminal of the register 61 is the H level. The output is at H level. Since the gate control signal is at the H level, the disappearance detection result output from the AND gate 62 is at the H level. Then, when the disappearance detection result received from the AND gate 62 is at the H level, the control signal generation unit 45 determines that the metastable has not yet disappeared.

  Then, the control signal generation unit 45 changes the extinction detection reset from the L level to the H level to reset the register 61 again. Further, the control signal generation unit 45 changes the gate control signal from the H level to the L level. As described above, the control signal generation unit 45 repeats the above operation (hereinafter also referred to as a detection operation) until the metastable disappears.

  On the other hand, when the metastable disappears, the random number data from the random number generator 1 is stabilized at the H level or the L level. Further, the output from the M sequence generation unit 2 is fixed at the H level or the L level. Therefore, the output from the EXOR gate 3 input to the clock input terminal of the register 61 becomes H level or L level, and the register 61 does not latch the H level of the data input terminal. Is maintained. The control signal generation unit 45 determines that the metastable has disappeared when the disappearance detection result received from the AND gate 62 is L level, and controls the random number storage unit 4 to control the random number data received from the EXOR gate 3. Is stored. In the figure, in the fourth detection operation, the control signal generation unit 45 determines that the metastable has disappeared because the disappearance detection result has become L level, and changes the random number storage signal from L level to H level. ing.

  Therefore, in the random number generation device according to the present embodiment, the metastable disappearance detector 6 detects the disappearance of the metastable, and the control signal generation unit 45 indicates that the metastable disappears from the metastable disappearance detector 6. After receiving the disappearance detection result, the random number storage unit 4 is controlled to store the random number data received from the EXOR gate 3. With such a configuration, a random number based on the life of the metastable can be generated more reliably, and the randomness can be improved.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Sixth Embodiment>
The present embodiment relates to a random number generator to which the operation content of the control signal generator 45 in the random number generator according to the fifth embodiment is added.

  Here, the operation when the random number generation device according to the present embodiment detects the disappearance of the metastable and generates a random number will be described.

  FIG. 16 is a time chart of each signal in the random number generation device according to the sixth embodiment of the present invention.

  If the metastable does not disappear even after a predetermined time has elapsed since the metastable is generated, that is, the control signal generation unit 45 maintains the H detection level from the AND gate 62 even if the detection operation is performed a predetermined number of times. In some cases, the random number storage unit 4 is controlled to store the random number data received from the EXOR gate 3. In the figure, the control signal generation unit 45 changes the random number storage signal from the L level to the H level since the disappearance detection result is also at the H level even in the x-th detection operation (x is a natural number of 1 or more). .

  Then, the control signal generation unit 45 changes the oscillation control signal and the M-sequence shift signal from the L level to the H level and starts generating the next random number.

  Therefore, the random number generation device according to the present embodiment can prevent the random number generation time from becoming too long. Further, in the random number generation device according to the present embodiment, a random number based on the life of the metastable is not generated. However, after the metastable is generated, the random number storage signal is changed from the L level to the H level before the metastable disappears. The randomness can be sufficiently improved by appropriately setting the period up to.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Seventh embodiment>
The present embodiment relates to a random number generation device in which the configuration of the control signal generation unit 5 in the random number generation device according to the first embodiment is changed.

FIG. 17 is a diagram showing a configuration of a random number generation device according to the seventh embodiment of the present invention.
With reference to the figure, the random number generation device includes a control signal generation unit 55 instead of the control signal generation unit 5 with respect to the random number generation device according to the first embodiment. The control signal generation unit 55 includes a register 71a to a register 71e.

  Registers 71a to 71e hold data received from a CPU (not shown) via a CPU bus at the timing of a write signal also received from the CPU, and the held data are respectively an oscillation control signal, an M-sequence shift signal, a random number storage signal, Output as extinction detection reset and gate control signal. Here, the CPU exists outside the random number generator.

  The disappearance detection result output from the AND gate 62 in the metastable disappearance detector 6 is output to the CPU via the CPU bus.

  FIG. 18 is a flowchart defining an operation procedure when the CPU controls the random number generation device according to the seventh embodiment of the present invention to generate a random number.

  First, the CPU changes the outputs of the registers 71a and 71b from the L level to the H level. That is, the CPU changes the oscillation control signal and the M-sequence shift signal from the L level to the H level. When the oscillation control signal changes from the L level to the H level, the ring oscillator 11 in the random number generation unit 1 enters the oscillation state. When the M-sequence shift signal changes from the L level to the H level, each register in the M-sequence generation unit 2 performs a shift operation, and the output of the M-sequence generation unit 2, that is, the logic level of the pseudorandom data is, for example, from the L level to the H level. The level changes (S1).

  Next, the CPU changes the outputs of the register 71a and the register 71b from the H level to the L level. That is, the CPU changes the oscillation control signal and the M-sequence shift signal from the H level to the L level. When the oscillation control signal changes from the H level to the L level, the ring oscillator 11 stops oscillating and a metastable is generated in the ring oscillator 11 (S2).

  After the metastable is generated in the ring oscillator 11, the CPU changes the output of the register 71d from the L level to the H level. That is, the CPU changes the disappearance detection reset from the L level to the H level. When the extinction detection reset becomes H level, the register 61 is reset, and the output of the register 61 becomes L level (S3).

  Next, the CPU changes the disappearance detection reset from the H level to the L level to release the reset state of the register 61. Then, after the reset state of the register 61 is released, the CPU changes the gate control signal from the L level to the H level, and reads the disappearance detection result output from the AND gate 62 via the CPU bus.

  When the disappearance detection result received from the AND gate 62 is L level, the CPU determines that the metastable has disappeared (YES in S5), and changes the output of the register 71c from L level to H level. That is, the CPU controls the random number storage unit 4 to store the random number data received from the EXOR gate 3 by changing the random number storage signal from the L level to the H level. The 1-bit random number data stored in the random number storage unit 4 is output as a random number to the CPU via the CPU bus, that is, the CPU reads out the 1-bit random number data stored in the random number storage unit 4 as a random number (S6).

  On the other hand, when the disappearance detection result received from the AND gate 62 is at the H level, the CPU determines that the metastable has not yet disappeared (NO in S5), and holds it as a variable of the “annihilation detection result 1 is added to the “number of readings” (S7).

  When the number of readings of the disappearance detection result is equal to or greater than the predetermined number of readings (YES in S8), the CPU changes the random number storage signal from the L level to the H level, thereby causing the EXOR gate 3 to be stored in the random number storage unit 4. Control to store the random number data received from. Then, the CPU reads 1-bit random number data stored in the random number storage unit 4 as a random number (S6).

  On the other hand, when the number of readings of the annihilation detection result is less than the predetermined number of readings (NO in S8), the CPU changes the annihilation detection reset from the L level to the H level to reset the register 61 again. (S3). Further, the CPU changes the gate control signal from the H level to the L level.

  When the CPU acquires random numbers for a predetermined number of bits (YES in S9), the CPU outputs the acquired random numbers to an encryptor, a hash function generator, and an M sequence generator (not shown) (S10). The encryptor, the hash function generation unit, and the M series generation unit are configured by a circuit or software incorporated in a CPU or the like.

  On the other hand, if the CPU has not acquired random numbers for a predetermined number of bits (NO in S9), the CPU changes the outputs of the register 71a and the register 71b from the L level to the H level and starts generating the next random number ( S1).

  Therefore, since the random number generation device according to the present embodiment can generate a random number based on the lifetime of the metastable as with the random number generation device according to the first embodiment, the randomness can be improved. .

  Furthermore, in the random number generation device according to the present embodiment, since the control signal generation unit 55 is configured by only five registers, the circuit scale is smaller than that of the random number generation devices according to the fifth to sixth embodiments. can do.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Eighth Embodiment>
The present embodiment relates to a random number generator for testing a ring oscillator.

  FIG. 19 is a schematic diagram of a random number generator for explaining a test method of the ring oscillator in the random number generator according to the eighth embodiment of the present invention.

  Referring to the figure, the random number generator includes a selector 73, a counter 74, and a plurality of ring oscillators 75.

Next, the operation of the random number generator when testing the ring oscillator will be described.
First, a control signal generation unit (not shown) outputs an oscillation control signal to the ring oscillator 75 so that the ring oscillator 75 is in an oscillation state.

  The selector 73 selects a signal received from the ring oscillator 75 to be tested among the signals received from the plurality of ring oscillators 75 and outputs the selected signal to the counter 74.

  Here, the ring oscillator 75 is, for example, the ring oscillator 11, the ring oscillator 13, and the ring oscillator 101. In the ring oscillator 11, any one output of the inverters 21 b to 21 e and the registers 23 a to 23 c is connected to the selector 73. In the ring oscillator 13, the output of any one of the NAND gates 41 a to 41 f and the registers 23 a to 23 c is connected to the selector 73. In the ring oscillator 101, the output of any one of the AND gate 33 and the inverters 34 a to 34 c is connected to the selector 73.

  The counter 74 counts the output of the test target ring oscillator 75 received via the selector 73 for a predetermined time.

  A test control unit (not shown) reads the count value of the counter 74 and calculates the oscillation frequency of the ring oscillator 75. When the oscillation frequency is within the predetermined range, the ring oscillator 75 to be tested is acceptable, and when the oscillation frequency is outside the predetermined range, the ring oscillator 75 to be tested is unacceptable.

  When the counter 74 counts the output of the register in the ring oscillator 11 and the ring oscillator 13, the count value is halved as compared with the case of counting the output of the inverter or the NAND gate. Calculated based on 2 times. Other configurations and operations are the same as those of the random number generator according to the first embodiment described above.

  Therefore, in the random number generation device according to the present embodiment, since the test of ring oscillator 75 can be performed inside the random number generation device, it is not necessary to output the output of ring oscillator 75 or the count value to the outside of the random number generation device. Test time can be shortened.

  The random number generator may not include the counter 74, and the output of the ring oscillator 75 may be output to the outside of the random number generator via the selector 73. With such a configuration, since a CPU or the like existing outside the random number generator can compare the output from the ring oscillator 75 with a predetermined test pattern to determine whether the ring oscillator 75 is acceptable, the counter 74 and A test control unit or the like becomes unnecessary, and the circuit scale can be reduced.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Ninth embodiment>
The present embodiment relates to a random number generation device in which a counter function is added by modifying the M-sequence generation unit 2 instead of the counter 74 in the random number generation device according to the eighth embodiment.

  FIG. 20 is a schematic diagram of a random number generator for explaining a ring oscillator test method in the random number generator according to the ninth embodiment of the present invention.

  Referring to the figure, the random number generation device is not provided with a counter 74 as compared with the random number generation device according to the eighth embodiment, and is provided with an M sequence generation unit 76 instead of M sequence generation unit 2. . Selector 73 selects an M-sequence shift signal received from a control signal generator (not shown) or an output of ring oscillator 75 and outputs the selected signal to M-sequence generator 76.

FIG. 21 is a schematic diagram of the configuration of the M sequence generation unit 76.
Referring to FIG. 4, M series generation unit 76 includes a selector 81, an M series logic 82, a counter logic 83, a selector 84, and a register 91.

  The M series logic 82 is an M series generation logic circuit arranged between the registers 91. The M-series logic 82 is either a circuit including the EXOR gate 92 or the OR gate 94 or a circuit only of wiring.

  The counter logic 83 is a logic circuit for counting the output of the ring oscillator 75 disposed between the registers 91, and realizes a counter function in combination with the register 91.

  The selector 81 selects the output of the preceding M-sequence logic 82 or the output of the counter logic 83 based on the M-sequence counter switching signal and outputs it to the register 91.

  The selector 84 selects the M-sequence generation clock, that is, the M-sequence shift signal, or the output of the ring oscillator 75 based on the M-sequence counter switching signal, and outputs it to the clock input terminal of each register 91.

  The register 91 uses the data selected by the selector 84 as a clock, holds the data selected by the selector 81 at the timing of this clock, and outputs it to the M-sequence logic 82 and the counter logic 83 in the next stage.

  When the ring oscillator test is performed, the selector 81 selects the output of the counter logic 83 and the selector 84 selects the output of the ring oscillator 75 based on the M-sequence counter switching signal. In this case, the M sequence generation unit 76 counts the output of the ring oscillator 75.

  On the other hand, in a normal operation in which random numbers are generated, the selector 81 selects the output of the M-sequence logic 82 and the selector 84 selects the M-sequence shift signal based on the M-sequence counter switching signal. In this case, the M sequence generation unit 76 generates an M sequence.

  Other configurations and operations are the same as those of the random number generator according to the first embodiment described above.

  Therefore, in the random number generation device according to the present embodiment, since the M-sequence generation unit 76 can be modified instead of the counter 74 and the output of the ring oscillator 75 can be counted, the random number generation according to the ninth embodiment The circuit scale can be reduced as compared with the device.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Tenth Embodiment>
The present embodiment relates to a random number generator in which a ring oscillator stuck-at fault test function is added to the ring oscillator 11 and the binarization unit 12 shown in FIG.

  FIG. 22 is a diagram illustrating a configuration of the ring oscillator 111 and the binarization unit 12 in the random number generation device according to the tenth embodiment of the present invention.

  Referring to FIG. 11, ring oscillator 111 further includes selectors 85 to 86 with respect to ring oscillator 11.

  The selector 85 selects the test data 1 or the output of the inverter 21e and outputs it to the inverter 21b. The selector 86 selects the test data 2 or the output of the inverter 21c and outputs it to the inverter 21d. The registers 23a to 23c can be read from the outside of the random number generator.

  First, a control signal generation unit (not shown) sets the oscillation control signal to the H level. When the oscillation control signal becomes H level, a loop including inverters 21c to 21e and NAND gates 22a and 22c is formed.

  Next, the CPU existing outside the random number generator outputs the test data 2 to the selector 86 via the CPU bus. Then, data corresponding to the test data 2 is held in the registers 23a to 23c.

  Then, the CPU reads the data held in the registers 23a to 23c via the CPU bus and compares the data with the test pattern for verification corresponding to the test data input to the random number generator, and determines whether the ring oscillator 111 is acceptable.

  Next, the control signal generator 5 changes the oscillation control signal from the H level to the L level. When the oscillation control signal changes from the H level to the L level, a loop including inverters 21b to 21e and NAND gates 22b and 22c is formed.

  Then, the CPU outputs test data 1 to the selector 85 via the CPU bus. Then, data corresponding to the test data 1 is held in the registers 23a to 23c.

  Then, the CPU reads the data held in the registers 23a to 23c via the CPU bus and compares the data with the test pattern for verification corresponding to the test data input to the random number generator, and determines whether the ring oscillator 111 is acceptable. The test data 1 and 2 are preferably test patterns generated by simulation and capable of detecting 100% of circuit failures.

  The registers 23a to 23c can be written from the outside of the random number generator. The output of the EXOR gate 24 can be read from the outside.

  The CPU writes the test data 3 to the registers 23a to 23c via the CPU bus. Then, the CPU reads the output of the EXOR gate 24 via the CPU bus and compares the verification result with the test pattern for verification corresponding to the test data 3 written in the registers 23a to 23c, and determines the pass / fail of the ring oscillator 111.

  Other configurations and operations are the same as those of the random number generator according to the first embodiment described above.

  Therefore, in the random number generation device according to the present embodiment, by inputting test data 1 and 2 to selector 85 and selector 86, the stuck-at fault of ring oscillator 111, that is, the input or output of each gate becomes a constant logic level. Faults that are fixed can be detected.

  Further, by inputting test data at two locations of the selector 85 and the selector 86 in the ring oscillator 111, it is possible to detect stuck-at faults at the input portions of the selector 85 and the selector 86 as well.

  The registers 23a to 23c can be read from outside the random number generator. With such a configuration, the test pattern for verification corresponding to the test data input to the random number generator is held in the random number generator, and a circuit for determining whether the ring oscillator 111 is acceptable or not by comparing these is generated. It is not necessary to provide in the apparatus, and the circuit scale can be reduced.

  The registers 23a to 23c can be written from the outside of the random number generator, and the output of the EXOR gate 24 can be read from the outside. With such a configuration, the stuck-at faults of the registers 23a to 23c and the EXOR gate 24 can be detected.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Eleventh embodiment>
The present embodiment relates to a random number generator in which a ring oscillator stuck-at fault test function is added to the ring oscillator 13 and the binarization unit 12 shown in FIG.

  FIG. 23 is a diagram showing a configuration of the ring oscillator 113 and the binarization unit 12 in the random number generation device according to the eleventh embodiment of the present invention.

  With reference to the figure, ring oscillator 113 further includes selectors 42 a to 42 f with respect to ring oscillator 13.

  The selectors 42a to 42f select the test data a to f or the oscillation control signal and output them to the NAND gates 41a to 41f.

  A CPU existing outside the random number generator outputs test data a to f to the selectors 42 a to 42 f via the CPU bus. The CPU can individually control the test data a to f to the selectors 42 a to 42 f. The test data a to f are preferably test patterns generated by simulation and capable of detecting 100% of circuit faults.

  As an operation when the random number generator performs a stuck-at fault test of the ring oscillator, for example, when a control signal generator (not shown) changes the oscillation control signal from L level to H level, among the selectors 42a to 42f, At least one of them selects test data, and the CPU outputs a signal similar to the oscillation control signal to the selector as test data. Then, whether or not metastable is generated in the ring oscillator 113 is confirmed by the CPU reading the output of the registers 23a to 23c or the EXOR gate 24 via the CPU bus.

  Other configurations and operations are the same as those of the random number generator according to the first embodiment described above.

  Therefore, in the random number generation device according to the present embodiment, a stuck-at fault of ring oscillator 113 can be detected by inputting test data to selectors 42a to 42f.

  Further, by inputting test data to each NAND gate of the ring oscillator 113, stuck-at faults can be detected in the input portions of the selectors 42a to 42f.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the random number generator which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram illustrating a configuration of a ring oscillator 11 and a binarization unit 12. 3 is a time chart for explaining operations of a ring oscillator 11 and a binarization unit 12; 3 is a diagram illustrating a configuration of an M sequence generation unit 2. FIG. 3 is a diagram illustrating a configuration of a control signal generation unit 5. FIG. 2 is a diagram showing a configuration of a ring oscillator 101. FIG. It is a time chart of each signal in the random number generator which concerns on the 1st Embodiment of this invention. 2 is a diagram illustrating a configuration of a ring oscillator 13. FIG. 2 is a diagram illustrating a configuration of a control signal generation unit 15. FIG. It is a time chart of each signal in the random number generator which concerns on the 2nd Embodiment of this invention. 3 is a diagram illustrating a configuration of a control signal generation unit 25. FIG. 3 is a diagram illustrating a configuration of a control signal generation unit 35. FIG. It is a time chart of each signal in the random number generator which concerns on the 4th Embodiment of this invention. It is a figure which shows the structure of the random number generator which concerns on the 5th Embodiment of this invention. It is a time chart of each signal in the random number generator which concerns on the 5th Embodiment of this invention. It is a time chart of each signal in the random number generator which concerns on the 6th Embodiment of this invention. It is a figure which shows the structure of the random number generator which concerns on the 7th Embodiment of this invention. It is the flowchart which defined the operation | movement procedure at the time of CPU generating the random number by controlling the random number generator which concerns on the 7th Embodiment of this invention. It is the schematic of the random number generator for demonstrating the test method of the ring oscillator in the random number generator which concerns on the 8th Embodiment of this invention. It is the schematic of the random number generator for demonstrating the test method of the ring oscillator in the random number generator which concerns on the 9th Embodiment of this invention. 4 is a schematic diagram of a configuration of an M sequence generation unit 76. FIG. It is a figure which shows the structure of the ring oscillator 111 and the binarization part 12 in the random number generator which concerns on the 10th Embodiment of this invention. It is a figure which shows the structure of the ring oscillator 113 and the binarization part 12 in the random number generator which concerns on the 11th Embodiment of this invention.

Explanation of symbols

  1 random number generation unit, 2,76 M sequence generation unit (pseudo random number generation unit), 3, 24, 92 EXOR gate, 4 random number storage unit, 5, 15, 25, 35, 45, 55 control signal generation unit, 6 metas Table extinction detector, 11, 13 ring oscillator (random number oscillator), 101 ring oscillator (clock oscillator), 12 binarization unit, 21a-21e, 34a-34c, 35 inverter, 22a-22c, 41a-41e NAND Gate, 23a-23c, 31a-31b, 52a-52c, 61, 71a-71e, 91 register, 32a-32b, 33, 62, 93 AND gate, 94 OR gate, 51 frequency divider, 42a-42f, 73, 81, 84 to 86 selector, 74 counter, 75, 111, 113 ring oscillator, 82 M series logic, 83 Counter logic, N21-N23, N41-N43 nodes.

Claims (20)

A random number generator for generating random number data based on the output of the circuit in the metastable in which the output of the circuit is unstable;
A random number storage for storing the random number data;
A random number generator comprising: a control unit that performs control to store the random number data output from the random number generation unit after the metastable disappears in the random number storage unit. The random number generator further includes:
A detector for detecting the disappearance of the metastable;
The random number generation device according to claim 1, wherein the control unit performs the control based on the detection result.   The random number generator according to claim 2, wherein the detection result can be read from the outside. The controller is
The random number generator according to claim 1, further comprising a frequency divider that divides a clock having a predetermined period, and performing the control based on the divided clock.   The random number generation device according to claim 1, wherein the control unit includes one or more registers, and performs the control based on an external write to the register. The random number generator further includes:
An M sequence generation unit for generating an M sequence;
An EXOR gate that outputs an exclusive OR of the M series and the random number data,
The random number generation device according to claim 1, wherein the random number storage unit stores the exclusive OR as the random number data. The M-sequence generation unit
A plurality of M-sequence logic units which are logic circuits for M-sequence generation;
A plurality of count logic units which are logic circuits for counting the output of the random number oscillator,
A plurality of first selectors for selecting an M-sequence generation clock or the random number oscillator output;
A plurality of second selectors for selecting the output of the preceding M-sequence logic unit or the output of the preceding count logic unit;
The data selected by the first selector is used as a clock, and the data selected by the second selector is held at the timing of the clock to the M-series logic unit and the counter logic unit of the next stage. The random number generator according to claim 6, further comprising a register for outputting. The random number generator
A random number oscillator for generating the metastable;
The random number generation device according to claim 1, further comprising: a binarization unit that generates the random number data based on an output of the random number oscillator in the metastable.   The random number generation device according to claim 8, wherein the control unit further includes one or more registers, and performs control to generate the metastable in the random number oscillator based on external writing to the registers. The random number generator further includes:
The random number generator according to claim 8, further comprising a counter that counts an output of the random number oscillator.   9. The random number generator according to claim 8, wherein the output of the random number oscillator can be output to the outside. The random number oscillator is
A plurality of delay circuits connected in a loop;
A third selector for selecting first input test data or an output of the delay circuit;
9. The random number generator according to claim 8, further comprising: second input test data; or a fourth selector that selects an output of the delay circuit different from the delay circuit whose output is connected to the third selector.   13. The random number generation device according to claim 12, wherein the binarization unit includes a register that holds an output of the delay circuit and from which the held data can be read from the outside. The binarization unit
A plurality of registers that respectively count the number of times the pulse signal in the metastable passes through each delay circuit of the random number oscillator;
An EXOR gate that outputs an exclusive OR of each count result,
9. The random number generator according to claim 8, wherein the register is writable from outside, and the output of the EXOR gate is readable from outside. The random number oscillator is
A plurality of delay circuits connected in a loop;
A plurality of fifth selectors arranged corresponding to the delay circuit,
The delay circuit inputs the output of the delay circuit in the previous stage and the output of the fifth selector,
The random number generation device according to claim 8, wherein the fifth selector outputs a control signal for generating the metastable or third input test data to the delay circuit. The random number generator further includes a clock oscillator for generating a clock,
The random number generation device according to claim 1, wherein the control unit performs the control based on a clock generated by the clock oscillator. The random number generator further includes:
An M sequence generation unit for generating an M sequence;
An EXOR gate that outputs an exclusive OR of the M series and the random number data,
The random number storage unit stores the exclusive OR as the random number data,
The M-sequence generation unit
A plurality of M-sequence logic units which are logic circuits for M-sequence generation;
A plurality of count logic units which are logic circuits for counting the clock oscillator output;
A plurality of first selectors for selecting an M-sequence generation clock or the clock oscillator output;
A plurality of second selectors for selecting the output of the preceding M-sequence logic unit or the output of the preceding count logic unit;
The data selected by the first selector is used as a clock, and the data selected by the second selector is held at the timing of the clock to the M-series logic unit and the counter logic unit of the next stage. 17. The random number generator according to claim 16, further comprising a register for outputting. The random number generator further includes:
The random number generation device according to claim 16, further comprising a counter that counts an output of the clock oscillator.   17. The random number generator according to claim 16, wherein the output of the clock oscillator can be output to the outside. A random number generator for generating random number data based on the output of the circuit in the metastable in which the output of the circuit is unstable;
A random number storage for storing the random number data;
A detector for detecting the disappearance of the metastable;
When the detector detects the disappearance of the metastable within a predetermined time from the occurrence of the metastable, the detector disappears the metastable after the disappearance of the metastable or even after the predetermined time elapses. A random number generator comprising: a control unit that performs control to store the random number data output from the random number generation unit in the random number storage unit after the predetermined time has elapsed.

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