JPH07295877A - Arbiter - Google Patents

Abstract

PURPOSE:To provide an arbiter capable of controlling the priority of shared resource access requests issued from plural devices without imposing any load on an external device and in addition, through simple configuration. CONSTITUTION:In the arbiter to arbitrate and control each of resource access requests RQ1 to RQ3 arising from plural devices sharing a resource, a first counter 3-1 to count the number of times of the reception of the resource access request about a prescribed device, a second counter 3-2 to count the number of times of the reception of the resource access request of the other devices, a comparator 4 to compare the value of the first counter 3-1 with the value of the second counter 3-2, and a gate circuit 2 to mask the resource access request of the prescribed device in accordance with a compared result in this comparator 4 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arbitration device for exclusively controlling access requests when a plurality of devices share resources such as a computer bus and memory.

[0002]

2. Description of the Related Art In an apparatus in which resources such as a computer bus and memory are shared by a plurality of devices, a resource access request signal generated from each device is accepted and resource access is controlled in accordance with a priority order peculiar to a system. Is commonly done. For example, the resource access request of the device having the highest priority is selected from the resource access requests of a plurality of devices occurring at any time, and the access of the shared resource is permitted only to that device. Although this method can configure the arbitration device with the simplest logic circuit, when the resource request signal of a device with a high priority occurs frequently, the device with a lower priority can access most shared resources. It has the drawback of disappearing. In view of this problem, many inventions have been made regarding an arbitration device that dynamically changes the priority order.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 4-15741, a priority storing means for storing the priority and a priority writing means for rewriting the contents of the priority storing means are provided. It is possible to change the arbitration priority of the arbitration device at a desired time by activating the priority writing means for changing the priority as needed.

Further, according to the technique disclosed in Japanese Patent Laid-Open No. 5-89034, a priority in which a value is updated each time a plurality of bus masters simultaneously issue a bus use request and the bus use right at that time is determined. By providing a control counter and a bus usage right waiting counter for each bus master, the arbitration priority of the arbitration device can be dynamically changed. In this technology, the initial values of the priority control counter and the bus usage right waiting counter are set by an external control device, and each bus master has a gradient in the frequency of acquiring the bus usage right so that the bus mastership It is possible to maintain a certain ratio of bus usage rights.

FIG. 9 is a block diagram of the image recording apparatus.

A document read by the scanner 101 is converted into a digital image signal, compressed by an image compression device 102 and converted into code data, and stored in a memory device 103 which is a shared resource. At the same time as this operation, the image decompressing device 105 reads the coded data from the memory device 103, performs decompression processing, sends the restored image data to the printer device 106, and the printer device 106 records the transferred image data. . In the memory device 103, the memory write access request of the image compression device 102 and the memory read access request of the image decompression device 105 compete with each other, so that the arbitration device 104 arbitrates each access.

When it is necessary to continuously transfer the image data to the printer device 106, the image expansion device 105 must continuously supply the image data. Therefore, it is necessary to supply the code data to the image decompression device 105 so that the decompression process is continuously performed. Therefore,
The arbitration device 104 performs arbitration in which the memory read access request of the image decompression device 105 has a higher priority than the memory write access request of the image compression device 102.

Considering that the original document currently being read by the scanner 101 is recorded at the same time, the code data generated by the image compression device 102 is immediately converted into the image decompression device 1.
It is taken in 05 and is expanded. In this case, the average memory read speed of the image decompression device 105 is determined by the image compression device 1.
When the average memory write speed of 02 is exceeded, the image decompression device 105 starts from the memory area where the code is not yet written.
Since the data is read out and normal recording cannot be performed, the arbitration device 104 must perform access arbitration so that the memory read speed does not exceed the memory write speed.

[0009]

However, in the image compression apparatus 102, if the compression rate changes depending on the input image data, the processing speed also changes accordingly. Similarly, in the image expansion device 105, the processing speed varies depending on the input code data. In order to ensure good data processing even in such a situation, the image compression device 102
Also, it is necessary to appropriately control the arbitration priority order in the arbitration device 104 each time the processing speed in the image decompression device 105 changes. In the conventional technique in which the arbitration priority can be changed from the outside, the control device such as a CPU (not shown) must frequently change the priority, which increases the load on the CPU. In the prior art in which the arbitration priority is dynamically changed each time the bus use right is determined, the arbitration priority is changed so that the bus use right is dispersed evenly. When it is necessary to urgently change the arbitration priority order, the initial values of the priority control counter and the bus right-of-use waiting counter must be changed frequently, and the load on the CPU also increases.

The present invention has been made in view of such circumstances, and it is possible to control the priority order of shared resource access requests issued from a plurality of devices without imposing a load on the external control device and with a simple configuration. An object is to provide an arbitration device.

[0011]

The arbitration device of the first invention counts the number of times a resource access request is received for a predetermined device, and the number of times a resource access request is received for other devices. Second counting means, comparing means for comparing the value of the first counting means with the value of the second counting means, and masking the resource access request of the predetermined device according to the comparison result in the comparing means. It is characterized in that it is provided with a masking means.

An arbitration device of a second invention is that the first counting means for accumulating the shared resource access times of a predetermined device, the second counting means for accumulating the resource access times of other devices, and the first Comparing means for comparing the value of the counting means with the value of the second counting means, and a resource access signal generating section for controlling the number of times of resource access of the predetermined device according to the comparison result in the comparing means. Characterize.

The arbitration device of the third invention comprises counting means for down-counting the number of times of receiving a resource access request for a predetermined device and up-counting the number of times of receiving a resource access request for other devices. It is characterized by comprising mask means for masking the resource access request of the predetermined device according to the count value of.
An arbitration device according to a fourth aspect of the present invention includes counting means for down-counting the number of shared resource accesses of a predetermined device and up-counting the number of resource access of other devices, and the predetermined device according to the count value of the counting means. It is characterized by comprising mask means for masking a resource access request of the device.

[0014]

According to the first aspect of the invention, the amount of data written and transferred to the shared resource at the time of arbitration can be found from the number of times the resource access request for the predetermined device is received and the amount of data written by one resource access. . In the arbitration device, the arbitration participation of the resource access requests of other devices is restricted so that the number of times of accepting the resource access request of the device reading the data is within the range of the number of times of accepting the resource access request for the predetermined device.

According to the second aspect of the invention, the amount of data written and transferred to the shared resource at the time when the arbitration is performed can be known from the cumulative number of times the shared resource is accessed by the predetermined device. In the arbitration device, the total number of read accesses when the resource access request of the device reading this data is permitted is
It is limited so that it is less than or equal to the total number of times of resource access for a predetermined device.

According to the third aspect of the invention, the counting means down-counts the number of resource access requests accepted for a predetermined device and up-counts the number of resource access requests accepted by other devices. Thus, the difference in the number of times of accepting two access requests at the time when arbitration is performed can be known. In the arbitration device, the arbitration participation of the resource access requests of other devices is restricted so that the number of times of accepting the resource access request of the device reading the data is within the range of the number of times of accepting the resource access request for the predetermined device.

According to the fourth invention, the counting means down-counts the resource access times of the predetermined device and up-counts the resource access times of the other devices, so that the arbitration is performed by the count value of the counting means. At this point, the difference between the amount of data transferred to the shared resource and the amount of data read out can be known. In the arbitration device, the total number of read accesses when the resource access request of the device for reading the data is permitted is limited to be equal to or less than the total number of resource access for the predetermined device.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an arbitration device according to a first embodiment of the present invention.

RQ1 to RQ3 are shared resource access request signals issued from different devices. In the following description, a second device (not shown) that issues RQ2 writes data to the shared resource,
It is assumed that the first device (not shown) which issues 1 reads and processes the shared resource access, and the priority order of the shared resource access increases from RQ3 to RQ1.

The access request arbitration unit 1 is a logic circuit that asserts only the output for the input having the highest priority among the resource access request inputs that arrive at any time. Here, the output 5-1 corresponds to the RQ1 input, the output 5-2 corresponds to the RQ2 input, and the output 5-3 corresponds to the RQ3 input.
The counters 3-1 and 3-2 are counter circuits each including a flip-flop that counts the number of times the outputs 5-1 and 5-2 of the access request arbitration unit 1 are asserted. The comparator 4 is a logic circuit that compares the outputs of the counters 3-1 and 3-2. The gate circuit 2 is a logic circuit that prohibits the input of the RQ1 to the access request arbitration unit 1 by the output of the comparator 4. The operation of each unit will be described with reference to FIG.

The access request arbitration unit 1 which has detected the assertion of the shared resource access request signal RQ1 of the first device at time t1 asserts only the output 5-1. By this signal, the counter 3-1 causes the previous count value n-3 to n-
Count up to 2. That is, the value C of the counter 3-1
NT1 indicates the number of times the access request arbitration unit 1 permits the shared resource access request of the first device. Similarly, the value CNT2 of the counter 3-2 represents the number of times the shared resource access request of the second device is permitted. Since the arbitration unit output 5-1 holds the asserted state while the first device is reading and accessing the shared resource, the shared resource access request signal RQ issued from the second device is held.
2 is reserved until time t2 when the read access of the first device ends. During the period from the time t2 to the time t3, the write access to the shared resource of the second device is performed and the counter 3 is started at the time t2 when the arbitration unit output 5-2 is asserted.
-2 counts up to the count value n. Then 2
Although the shared resource read access of the first device is permitted consecutively, the count value of the counter 3-1 becomes n at time t4, which coincides with the value of the counter 3-2. In other words, this read access indicates that the first device has read all the data written in the shared resource by the second device. Therefore, if the shared resource read access of the first device is further permitted, the first device will read meaningless data. The comparator output CMP becomes asserted at time t4 and masks the output of the access request signal RQ1 from the gate circuit 2. As a result, the access request of the first device during this period is ignored by the access request arbitration unit 1, and unnecessary access of the first device is prohibited. When the read access of the first device ends at time t5,
The time t at which the shared resource access request of the third device is subsequently permitted and the shared resource access of the third device ends.
During the period up to 6, the arbitration unit output 5-3 holds the asserted state.

The access request signal RQ1 having the highest priority is asserted during the period from time t6 to time t7, but the gate circuit 2 masks the access request signal RQ1 because the comparator output CMP is asserted. Therefore, when the shared resource access request signal RQ2 of the second device having a lower priority than the first device is asserted at time t7, the access request arbitration unit 1 gives priority to the access request arbitration unit 1 and outputs the access request arbitration unit. 5-2 is asserted. At the same time, the count value of the counter 3-2 changes from n to n + 1.
Therefore, the comparator output CMP is negated, the access request signal RQ1 mask in the gate circuit 2 is released, and the time t at which the write access of the second device ends.
8, the read access of the first device is permitted, the arbitration unit output 5-1 asserts until time t9, and the counter 3-
1 counts up to n + 1.

As is clear from this description, the access right is no longer given to the first device when the number of times the first device and the second device have received the shared resource access match, and at this time, the priority is changed from the outside. There is no special control such as.

The access right may not be given to the first device when a predetermined difference occurs in the number of times the first device and the second device receive shared resource access.
Furthermore, the condition for the shared resource access request of the first device to be able to participate in the arbitration is not limited to the time when the access counts do not match as in the embodiment, but is set to the time when the access counts differ by a predetermined amount or more. Good.

Next, a second embodiment according to the present invention will be described.

FIG. 3 is a block diagram of an arbitration device according to a second embodiment of the present invention. In the figure, blocks having the same functions as those in the first embodiment are designated by the same numbers as in FIG.

Access control signal generators 10-1 to 10-
Reference numerals 3 to 14-3 designate shared resource access signals (memory read control signals and memory write control signals for the memory which are shared resources) of the first devices to 3 respectively.
And response signals 15-1 to 15-3 to the corresponding device
Is a sequential logic circuit that generates by detecting that the arbitration unit outputs 5-1 to 5-3 are asserted. Counter 11-
Reference numerals 1 and 11-2 are counter circuits for counting the number of times the shared resource access signal 14-1 of the first device and the shared resource access signal 14-2 of the second device are asserted, respectively. The comparator 12 includes counters 11-1 and 11-2.
Is a logic circuit that compares the outputs of the. The access signal synthesizer 13 includes an access control signal generator 1 for each device.
Shared resource access signal 1 generated in 0-1 to 10-3
It is a block that combines 4-1 to 14-3 into one and gives them to a shared resource (not shown), and is a logic circuit composed of an OR gate or the like.

The operation of the second embodiment will be described with reference to FIG.

The access request arbitration unit 1 which has detected the assertion of the shared resource access request signal RQ1 of the first device at time t11 asserts only the output 5-1. Since the arbitration unit output 5-1 is asserted, the access control signal generation unit 10-1 is activated, and the shared resource access signal 14-1 and the response signal 15-1 are generated. The access signal 14-1 is a shared resource read signal, and the counter 11-1 counts up at the rising edge of this signal. Here, it is assumed that the read access is permitted four times with respect to one shared resource access request from the first device. Therefore, as shown in FIG. 4, the shared resource access signal 14-1 and the response signal 15-1 are each asserted four times. The value CNT3 of the counter 11-1 has increased from n-3 to n + 1 when the access of the first device ends at time t12. Shared resource access request signals RQ2, RQ3 of the second device and the third device until time t12
However, at time t12, the access right is given to the second device having a higher priority and the arbitration unit output 5-2 is asserted. As a result, the access control signal generation unit 10-2 is activated, and the shared resource access signal 14-2 and the response signal 1 which are shared resource write signals.
5-2 is generated. The shared resource write access of the second device is performed twice until the time t13, and the counter 11-
The value of 2 increases from n + 2 to n + 4. At time t13, the access of the second device ends, but at this time, the access requests of the first device and the third device are in conflict,
The access right is given to the first device having the higher priority, and the arbitration unit output 5-1 is asserted. After that, at the time t14 when the shared resource read access of the first device is performed three times, the value of the counter 11-1 and the counter 1
The values of 1-2 match at n + 4 and the comparator output 16 asserts. Accordingly, the access control signal generation unit 10-1
Then, the fourth access is prohibited, the arbitration unit output 5-1 is negated to end the access of the shared resource, and at the same time, the access request arbitration unit 1 outputs the shared resource access request signal R.
Arbitration for the next access is started ignoring Q1.
At this point, the access right is finally given to the third device, and the shared resource write access of the third device ends at time t15. At time t15, the access right is given to the second device, the value of the counter 11-2 is increased from n + 4 to n + 6 by the two shared resource write accesses, and the comparator is changed when the value of the counter 11-2 is changed to n + 5. The value of output 16 negates. Then, at time t16 when the shared resource write access of the second device ends, the shared resource read access of the first device, which was suspended, is permitted again, and time t when the fourth read access ends.
In 17, the negation of the access request signal RQ1 is detected, the arbitration unit output 5-1 becomes the negated state, and the read access of the first device ends.

In the second embodiment, when the shared resource read access count of the first device and the shared resource write count of the second device match, the read access of the first device is temporarily stopped and the access is terminated. While giving the access right to the other device, the access right is not given to the first device. Similar to the first embodiment, at this time, no special control such as priority change from outside is entered.

In the above two embodiments, the case where the first device continues to read the data written by the second device has been described. However, the first device writes new data in the area where the second device has read the data. It is obvious that each invention can be applied to such cases.

Next, a third embodiment according to the present invention will be described.

FIG. 5 is a block diagram of an arbitration device according to a third embodiment of the present invention. In the figure, the blocks having the same functions as those in the first embodiment and the signal names are given the same numbers as in FIG.

The up / down counter 20 counts down when the output 5-2 of the access request arbitration unit 1 is asserted, and counts up when the output 5-1 of the access request arbitration unit 1 is asserted. It is an up / down counter circuit configured. Output MSB of up / down counter 20 (= Mast Sign
ifificant Bit: most significant bit) is a sign bit. MSB is 1 when the count value is 0 or more and 0 and less than 0. The gate circuit 21 shows the operation of each unit which is a logic circuit for prohibiting the input of RQ1 to the access request arbitration unit 1 by the output of the up / down counter 20.
Will be explained.

The access request arbitration unit 1, which has detected the assertion of the shared resource access request signal RQ1 of the first device at time t1, asserts only the output 5-1. This signal causes the up / down counter 20 to count up from the previous count value (CNT in the figure) -2 to -1. Since the arbitration unit output 5-1 holds the asserted state while the first device is reading and accessing the shared resource, the shared resource access request signal RQ2 issued from the second device.
Is the time t at which the read access of the first device ends.
Holds up to 2. The period from time t2 to t3 is the second
The write access to the shared resource of the device is performed and the up / down counter 20 counts down to the count value −2 at time t2 when the arbitration unit output 5-2 is asserted.
Thereafter, the shared resource read access of the first device is permitted twice consecutively, but at time t4, the count value of the up / down counter 20 becomes 0 and the MSB becomes 0. In other words, this read access indicates that the first device has read all the data written in the shared resource by the second device. Therefore, if the shared resource read access of the first device is further permitted, the first device will read meaningless data. The up / down counter output MSB becomes an assert state at time t4 and masks the output of the access request signal RQ1 from the gate circuit 21. As a result, the access request of the first device during this period is ignored by the access request arbitration unit 1, and unnecessary access of the first device is prohibited. When the read access of the first device ends at time t5, the shared resource access request of the third device is continuously permitted, and the arbitration unit output 5-3 until the time t6 when the shared resource access of the third device ends.
Holds the asserted state. The access request signal RQ1 having the highest priority is asserted during the period from time t6 to time t7, but the access request signal RQ1 is masked by the gate circuit 2 because the up-down counter output MSB is asserted. Therefore, when the shared resource access request signal RQ2 of the second device having a lower priority than the first device is asserted at the time t7, the access request arbitration unit 1 gives priority to the access request arbitration unit 1 and outputs the access request arbitration unit. 5-2 is asserted. At the same time, since the count value of the up / down counter changes from 0 to -1, the up / down counter output MSB is negated, the access request signal RQ1 mask in the gate circuit 21 is released, and the write access of the second device ends. At t8, the read access of the first device is permitted, the arbitration unit output 5-1 asserts until time t9, and the up / down counter counts up to 0. As is apparent from this description, the access right is not granted to the first device when the shared resource access acceptance times of the first device and the second device match. Similar to the first and second embodiments, no special control such as priority change from outside is entered at this time.

The access right may not be given to the first device when a predetermined difference occurs in the number of times the first device and the second device receive shared resource access.
Furthermore, the condition for the shared resource access request of the first device to be able to participate in the arbitration is not limited to the time when the access counts do not match as in the embodiment, but is set to the time when the access counts differ by a predetermined amount or more. Good.

Next, a fourth embodiment according to the present invention will be described.

FIG. 7 is a block diagram of an arbitration device according to a fourth embodiment of the present invention. In the figure, blocks having the same functions as those in the first embodiment are designated by the same numbers as in FIG.

Access control signal generators 10-1 to 10-
Reference numerals 3 to 14-3 designate shared resource access signals (memory read control signals and memory write control signals for the memory which are shared resources) of the first devices to 3 respectively.
And response signals 15-1 to 15-3 to the corresponding device
Is a sequential logic circuit that generates by detecting that the arbitration unit outputs 5-1 to 5-3 are asserted. The up / down counter 30 controls the shared resource access signal 14 of the first device.
It is an up-down counter circuit that counts down when -1 is asserted and counts up when the shared resource access signal 14-2 of the second device is asserted.
The access signal synthesizing unit 13 collects the shared resource access signals 14-1 to 14-3 generated by the access control signal generating units 10-1 to 10-3 for each device into one block and gives the shared resource to a shared resource (not shown). Is a logic circuit composed of an OR gate and the like.

The operation of the fourth embodiment will be described with reference to FIG.

The access request arbitration unit 1 which has detected the assertion of the shared resource access request signal RQ1 of the first device at time t11 asserts only the output 5-1. Since the arbitration unit output 5-1 is asserted, the access control signal generation unit 10-1 is activated, and the shared resource access signal 14-1 and the response signal 15-1 are generated. The access signal 14-1 is a shared resource read signal, and the up / down counter 30 counts up at the rising edge of this signal. Here, it is assumed that the read access is permitted four times with respect to one shared resource access request from the first device. Therefore, as shown in FIG. 4, the shared resource access signal 14-1 and the response signal 15-1 are each asserted four times. The value of the up / down counter 30 is − when the access of the first device is completed at time t12.
It has increased from 5 to -1. Second by the time t12
Shared resource access request signals RQ2, R of device and 3
Although Q3 is asserted, at time t12, the access right is given to the second device having a higher priority and the arbitration unit output 5-2 is asserted. As a result, the access control signal generator 10-2 is activated, and the shared resource access signal 14-2 and the response signal 15-2, which are shared resource write signals, are generated. By the time t13, the shared resource write access of the second device is performed twice, and the value of the up / down counter 30 decreases from -1 to -3 at the rising edge of the shared resource access signal 14-2. Time t
The access of the second device ends at 13, but at this time, the access requests of the first device and the third device compete with each other, and the access right is given to the first device having a high priority, and the arbitration unit outputs. 5-1 is asserted. After that, at the time t14 when the shared resource read access of the first device is performed three times, the up / down counter 30
Becomes 0 and MSB is asserted. As a result, the access control signal generation unit 10-1 prohibits the fourth access, negates the arbitration unit output 5-1 to temporarily terminate the access to the shared resource, and at the same time, the access request arbitration unit 1
Then, the shared resource access request signal RQ1 is ignored and arbitration for the next access is started. At this time, the access right is finally given to the third device, and the third device is given the access right at time t15.
The shared resource write access of the device ends. At time t15, the access right is given to the second device, and the up / down counter 3 is accessed by the shared resource write access twice.
The value of 0 decreases from 0 to -2, and the up / down counter 3
The MSB is negated when the value of 0 changes to -1. Then, at the time t17 when the shared resource read access of the first device, which was suspended at the time t16 when the shared resource write access of the second device ends, is re-authorized and the fourth read access ends, the access request signal RQ1 is negated. Is detected, the arbitration unit output 5-1 becomes a negated state, and the read access of the first device is completed.

In the fourth embodiment, when the shared resource read access count of the first device and the shared resource write count of the second device match, the read access of the first device is temporarily stopped and the access is terminated. While giving the access right to the other device, the access right is not given to the first device. Similar to the first to third embodiments, at this time, no special control such as changing the priority is entered from the outside.

[0044]

As described above, according to the first aspect of the present invention, the number of times of access acceptance of each of a plurality of devices is counted by a counter or the like, and the number of times of access of resource access request relating to a predetermined device and other devices. The arbitration participation of the resource access requests of devices other than the predetermined device is restricted according to the magnitude relation of the number of access acceptances of the devices, so that hardware implementation is easy and the arbitration order can be controlled without imposing a load on the external control device. effective. According to the second aspect of the present invention, the total number of shared resource access times of each of the plurality of devices is counted by a counter or the like, and the total number of access times of the predetermined device and the total number of access times of the other devices are compared according to the magnitude relationship. , It is possible to control the arbitration order without imposing a load on the external control device because the arbitration participation of resource access requests of devices other than the predetermined device can be restricted and the number of times of resource access can be restricted.
This has the effect of dynamically controlling the amount of transfer data when a single access request is permitted.

Further, according to the third and fourth inventions, the output of the up / down counter is used for the magnitude relation of the access acceptance number and the magnitude relation of the access number.
This has the effect of simplifying the hardware.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first arbitration device according to the present invention.

FIG. 2 is a timing diagram illustrating an operation of the first arbitration device.

FIG. 3 is a configuration diagram of a second arbitration device according to the present invention.

FIG. 4 is a timing diagram illustrating an operation of the second arbitration device.

FIG. 5 is a configuration diagram of a third arbitration device according to the present invention.

FIG. 6 is a timing diagram illustrating an operation of the third arbitration device.

FIG. 7 is a configuration diagram of a fourth arbitration device according to the present invention.

FIG. 8 is a timing diagram illustrating an operation of the fourth arbitration device.

FIG. 9 is a diagram illustrating a problem of the conventional technique.

[Explanation of symbols]

1 ... Access request arbitration unit, 2 ... Gate circuit, 3-1 and 3
-2 ... Counter, 4 ... Comparator, 10-1 to 10-3 ... Access control signal generator, 11-1, 11-2 ... Counter, 12 ... Comparator, 13 ... Access signal synthesizer, 20 ...
..Up-down counters, 21 ... Gate circuits, 3
0 ... Up-down counter, 101 ... Scanner, 1
02 ... Image compression device, 103 ... Memory device, 104 ... Arbitration device, 105 ... Image decompression device, 106 ... Printer device

Claims (4)

[Claims] 1. An arbitration device for arbitrating and controlling resource access requests generated from a plurality of devices sharing a resource, and first counting means for counting the number of times a resource access request for a predetermined device is received. For counting the number of times resource access requests from other devices are accepted
Counting means, comparing means for comparing the value of the first counting means with the value of the second counting means, and masking means for masking the resource access request of the predetermined device according to the comparison result in the comparing means. An arbitration device comprising: 2. An arbitration device for arbitrating and controlling respective resource access requests generated from a plurality of devices sharing resources, and a first counting means for accumulating the number of shared resource accesses of a predetermined device, and other means. A second counting means for accumulating the number of times of resource access of the device;
Comparing means for comparing the value of the counting means with the value of the second counting means, and a resource access signal generating section for controlling the number of times of resource access of the predetermined device according to the comparison result in the comparing means. Characterizing arbitration device. 3. An arbitration device that arbitrates and controls resource access requests generated from a plurality of devices sharing a resource, down-counts the number of times a resource access request for a predetermined device is accepted, and resources of other devices. An arbitration device comprising: counting means for up-counting the number of times an access request is accepted, and mask means for masking a resource access request of the predetermined device according to a count value of the counting means. 4. An arbitration device that arbitrates and controls respective resource access requests generated from a plurality of devices sharing a resource, downcounts the number of shared resource accesses of a predetermined device, and counts the number of resource accesses of other devices. An arbitration device comprising: counting means for up-counting, and masking means for masking a resource access request of the predetermined device according to a count value of the counting means.