JP2615743B2 - Random number generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a random number generator for generating a pseudo random number.

[Conventional technology]

If you want to control various systems at different time intervals, generate random numbers inside each system,
In some cases, it is desired to control the system by using this random number as a control time interval. In such a case, the following random number generator has been used.

In other words, a series of random numbers such as a normal random number or a uniform random number previously obtained from a random number table or the like is stored by the memory means, and when a random number request signal is generated, the random number existing at the address indicated by the address pointer is stored. 2. Description of the Related Art A random number generator for outputting a signal is widely known.

Figure 3 is shows an example of a conventional random number generator, the random number request signals S ₁ to the address pointer 3 enters,
The value of the address pointer 3 at that time is input to the random number table 2, and the value of the random number existing at the address corresponding to the value is output as the random number 5.

When a random number is actually generated in the system, it is realized by software in a microprocessor, for example.

[Problems to be solved by the invention]

As described above, the method of preparing a random number sequence for each system is not practical because it is not suitable for mass production. On the other hand, having a plurality of types of random number sequences in one microprocessor requires a large memory capacity. It is desirable to use one kind of random number sequence because it leads to an increase.

However, there is no problem when the random number generator is used for one system, but when controlling a plurality of systems, when one type of random number sequence is used, if the address pointers 3 of each system match once, , The generated random numbers 5 also match, and each system can no longer be controlled at random, causing a problem that the systems do not work properly.

Therefore, the present invention has been made in view of the above-described problems, and an object of the present invention is to generate a random number in which each output random number does not have the same value when used in a plurality of systems. It is to provide a device.

[Means for solving the problem]

The present invention provides a random number table in which a random number table or a series of random numbers obtained in advance by calculation or the like is stored, and an address for outputting a series of random number address values stored by the random number table when a random number request signal is generated. A self-running counter that increments a counter value at fixed time intervals in a random number generator that includes a pointer;
Update request signal generating means for outputting an update request signal for updating the output value of the address pointer at a predetermined timing; and when the update request signal is output from the update request signal generating means, The object is achieved by replacing the counter value of the counter with the output value of the address pointer.

Hereinafter, the present invention will be described with reference to the drawings given as one embodiment.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Reference numeral 1 denotes a self-running counter, which is a counter that independently measures time in the system, such as a timer in a microprocessor that increments a value at regular time intervals.

Reference numeral 2 denotes a random number table which stores a series of random number sequences such as a normal random number and a uniform random number obtained from a random number table or the like, and includes a memory means such as a ROM (Read Only Memory).

3 is the address pointer, a memory means for pointing to one of the addresses read any value in the random number table 2 when the random number request signal S ₁ is inputted, RMA (Random access M
emory) is used.

4 is a random number output number counter constituting the update request signal generating means counts the number of output times of the random number 5 output from the random number table 2, and outputs an a update request signal S ₂ output count reaches a predetermined value is there. This update request signal S ₂
It is input to a gate circuit 6 described later.

6 is a gate circuit, interposed between the free-running counter 1 and the address pointer 3, the output signal of the free-running counter 1, the update request signal S ₂ is to be inputted only to the address pointer 3 upon the occurrence It is for.

 Next, the operation of the present embodiment will be described.

When entering the random number request signals S ₁ to the address pointer 3, output from the address pointer 3 address value to the random number table 2, and outputs the random number value stored in the address corresponding to the address value as a random number 5. The address pointer 3 updates its value after outputting the random number 5. As an updating method, for example, it is sufficient to normally increment the value by a predetermined value, and to return to the initial value when the updated value does not indicate an address value in the random number table 2.

The random number output number counter 4 increments the counter value every time the random number 5 is output from the random number table 2. When the counter value reaches the preset value, and outputs the update request signal S ₂ to the gate circuit 6, the gate circuit 6 is to open the gate.

Updated value of the address pointer 3 is the replacement for the counter value of the free-running counter 1 at the time when the update request signal S ₂ enters. If the counter value of the free-running counter 1 at this time does not point to an address value in the random number table 2, an appropriate address value is obtained in the address pointer 3 by, for example, using only lower bits. Is corrected as follows.

FIG. 2 is a block diagram showing another embodiment of the present invention.

In this embodiment, a pulse generator 7 is used as the update request signal generator. As a specific example of the pulse generating means 7, a timer pulse output at a fixed time interval, a trigger pulse generated when a condition predetermined in the system is satisfied, or the like may be used.

In the case of a conventional random number generating device in which it is difficult to sequentially read the random number table 2, in a plurality of systems, once the address pointers 3 of each system match,
Although the control of each system will be completely synchronized with the control of the other systems, in the present invention, any of the embodiments also, the update request signal S ₂ so updates the value of the address pointer 3, the system is temporarily Can work again in a random relationship with each other.

〔The invention's effect〕

The present invention is directed to a random number table in which a random number table or a series of random numbers obtained in advance by calculation or the like is stored. A self-running counter that increments a counter value at fixed time intervals in a random number generator that includes a pointer;
Update request signal generating means for outputting an update request signal for updating the output value of the address pointer at a predetermined timing; and when the update request signal is output from the update request signal generating means, Since the counter value of the counter is replaced by the output value of the address pointer, a random number generator can be provided in which each output random number does not have the same value when used in a plurality of systems.

[Brief description of the drawings]

 FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional example. 1 self-running counter, 2 random number table 3 address pointer 4 random number output counter 5 random number 6, gate circuit.

Claims (2)

(57) [Claims] 1. A random number table in which a random number table or a series of random numbers previously obtained by calculation or the like is stored, and when a random number request signal is generated, an address value of the series of random numbers stored in the random number table is output. A self-running counter for incrementing a counter value at regular time intervals in a random number generator including an address pointer;
Update request signal generating means for outputting an update request signal for updating the output value of the address pointer at a predetermined timing predetermined at least one of the number of times output from the random number table or time, When an update request signal is output from the update request signal generating means,
A random number generator, wherein a counter value of the self-running counter is replaced with an output value of the address pointer. 2. A random number output number counter for counting the number of random numbers output from the random number table and outputting an update request signal when the counted value reaches a predetermined value as the update request signal generating means. 2. The random number generator according to claim 1, wherein the random number generator is used.