JP3422501B2 - Access mediation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an information processing apparatus, a communication exchange, particularly an ATM exchange, and other systems having a plurality of resources commonly connected by a bus.
Here, the resource means a memory device, an output device, a display device, an input device, a printing device, a functional unit, and other equipment accompanied by hardware for operating the system.

The present invention relates to arbitration of a plurality of access requests generated from within a system with respect to a plurality of shared resources arranged in one system.

[0003]

2. Description of the Related Art Arbitration of access requests according to the prior art will be described with reference to FIG. FIG. 6 is a conceptual diagram for explaining the operation of the ring arbiter. The number of the resource of the request destination is displayed as an access request from each of the request generation sources R (1) to R (8). Arbitration control is executed for each resource. Arbitration control is being executed for the m-th resource S (m) in FIG. Each request source R (1) ~ R
The access request from (8) is searched and it is searched whether or not there is any requesting access to the resource S (m). Now in this example, the second request source R
(2) issues an access request to the m-th resource.
In arbitration control, when this is found, this request source is connected to the resource S (m). When one is connected, the other request sources are disconnected.

If there is only one request generation source R (1) to R (8) that is issuing an access request to the m-th resource S (m), the request will be accepted immediately. If there is any conflict between them, arbitration is performed, one is selected, and the request is accepted. The arbitration logic can be set in various ways. Here, it is assumed that the request generation sources R (1), R (2), ..., R (n) are cyclically executed. This logic is equivalent to the request source R (1) to R (8).
(1) to R (8) can be prioritized and any other logic can be set. This is based on the control method of the ring arbiter, and it is possible to construct a network in which a plurality of request generation sources access a plurality of resources by combining a plurality of configurations as shown in FIG.

FIG. 7 shows a network configuration example. FIG. 7 is a diagram showing a network configuration. In this model, there are eight access request sources R (1) to R (8) and eight resources S (1) to S (8) that accept the access requests. These are respectively connected to the input terminal group and the output terminal group of the matrix switch means. The matrix switch means may be provided with hardware of a matrix structure as shown in the drawing, or may be virtual one composed of a logic circuit having the illustrated matrix function capable of transmitting an access request. The number of access request sources and the number of resources are not necessarily equal.

The access request sources R (1) to R (8) generate access requests one after another. Since access requests are generated according to the circumstances of the source, a plurality of access requests may compete for one resource at the same time. The contention is arbitrated by the matrix switch means, and one access request generation source transmits the access request to one resource of a request destination. At this time, the ring arbiter RA
Each of (1) to RA (8) sweeps an access request as shown by an arrow in FIG. 7, and when the corresponding access request is reached, the access request is cleared via the intersection C (n, m). Only one is transmitted to the resource side, and the resource accepts the access request.

When one access request is accepted,
Information indicating that the request has been accepted is transmitted to the request source that has transmitted the access request. By accepting one access request, another access request sent to the ring arbiter is made to wait, and the other access request is detected at the next timing or at the next timing. After the access request is accepted, processing such as transfer of necessary data via this matrix switch means or via another bus signal line is executed.

[0008]

In such access request arbitration control, the ring arbiters RA (1) to RA (8) for performing arbitration in the case of contention each request in one time slot. Only one access request from the source can be accepted.

Although the conventional device shown in FIG. 6 has eight request generation sources R (1) to R (8), the number is actually several tens or several hundreds. , At this time, the speed at which the ring arbiter goes around becomes a time that cannot be ignored.

An object of the present invention is to improve this, and to provide an access arbitration device that shortens the contention arbitration time by dividing a ring arbiter for parallel processing.

[0011]

According to the present invention, one access request generated from a plurality of N request generation sources is selected for each time slot, and one access request is shared by the N access request sources. It is an access arbitration device that gives access rights to resources.

Here, a feature of the present invention is that the N request generation sources are arranged in the order of access request selection.
They are arranged in a row, and immediately before that, access is granted.
The priority of the access request source fell to the lowest
Immediately after the access request source that fell to the bottom
It is assumed that a virtual boundary line is set to
N first access provided corresponding to the request source
Right arbitration circuit and N first access right arbitration circuits
Are arranged in a row in the corresponding N request sources.
Divide into groups to preserve order, and each of them
Group has the highest priority for each time slot.
The first ring arbiter that selects access requests and this first
Each group's access selected by one ring arbiter
A second access right arbitration circuit for receiving the access request;
From the second access right arbitration circuit for each time slot
With a second ring arbiter that selects one access request
The N first access right arbitration circuits are
Request source to be upstream or downstream of the virtual boundary line
It recognizes the sign that is information on whether
The right arbitration circuit has at least the first access request
First access right arbitration selected by one ring arbiter
Receiving the identification recognized by the circuit, the second ring
The arbiter has the highest priority according to this sign.
Select only one access request for a group,
The first ring arbiter and the second ring arbiter
Access right arbitration circuit and the second access right
The access right arbitration circuit is selected according to the access right arbitration circuit.
If the sign is downstream, the priority is high, and
If there are multiple access right arbitration circuits with the same sign,
Higher priority for access right arbitration circuit located upstream
It is about to be done as a thing .

The first ring arbiter is the glue
Means for cyclically scanning request sources in a cluster
It is desirable to include .

[0014] or it is preferable according to the sequence of their from the start point to the end point and from the end point comprises means for parallel scanning the to the start point.

[0015]

The request source is divided into a small number of groups, and a plurality of groups formed by this grouping are set as the first group. A boundary is set so that the request source that has obtained the previous access permission has the lowest priority this time, and the priority array is divided into two groups. The two groups formed by this grouping are called the second group. The array containing the request source that received the previous access permission is the second group with the lower priority, and the request source contained in that array is the request source included in the other second group. It has a lower priority than the source.

Starting from the head of the array of the second group having the higher priority, the access source is finally granted the access permission to the request source having the access request first. next time,
A boundary is set so that the request source to which the access permission is given this time has the lowest priority.

As a contention arbitration procedure, contention arbitration is performed by the first arbitration means for each first group. At this time, a request generation source having an access request for each first group outputs an indicator indicating its priority to the second arbitration means.
The second arbitration means latches this indicator and identifies its priority.

As described above, the first and second arbitration means perform processing in parallel over a plurality of groups, so that a large-scale ring arbiter is used alone without grouping, Competitive mediation can be performed in a short time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of the first embodiment of the present invention.

According to the present invention, 16 request sources R (1) to R
Access request generated from (16) is 1 for each time slot.
Request sources R for these 16 accesses are selected individually.
It is an access arbitration device that gives an access right to one resource S (1) shared by (1) to R (16).

Here, the feature of the present invention is that
The six request sources R (1) to R (16) are divided into four groups, and each of the four groups selects the highest priority access request for each time slot . A
Access right arbitration circuits CT (1) to CT (16) and the first ringer
A first arbitration means comprising a arbiter, a first ring earth from the first access arbiter CT this (1) ~CT (16)
The second access arbitration circuits RAI (1) to RAI (4) and the second access arbitration circuits RAI (1) to RAI (4) for selecting one access request for each time slot for the access request of each group selected by the bitter
Bei <br/> example a second arbitration hand stage comprising a second ring arbiter, the second access arbitration circuit RAI (1) ~RAI (4) , at least a first access arbiter CT ( 1) ~ C
Group G (1) with access request selected at T (16)
.About.G (4), the second access arbitration circuits RAI (1) .about.RAI (4) include indicators D1.about.D4 representing the current priorities of the groups G (1) .about.G (4). This sign D
It includes a means for selecting only one access request of the groups G (1) to G (4) having the highest priority according to 1 to D4.

Next, the operation of the first embodiment of the present invention will be described. 16 first access right arbitration circuits CT (1) to CT
Of the (16), the first access right arbitration circuit CT (1) to CT
An access right arbitration circuit group G (1) and a first access right arbitration circuit CT (5) to CT (8) are a set composed of (4).
Access right arbitration circuit group G
(2) The access right arbitration circuit group G (3) is a set of the first access right arbitration circuits CT (9) to CT (12).
, A set of the first access right arbitration circuits CT (13) to CT (16) is an access right arbitration circuit group G (4), and the first access right arbitration circuit groups G (1) to G
(4), each individual ring arbiter RA1 (1) ~
RA1 (4) is in patrol.

Here, the first access right arbitration circuit C last time
If T (6) obtains the access right, apart from the distinction between the access right arbitration circuit groups G (1) to G (4), there is a difference between the first access right arbitration circuits CT (6) and CT (7). First access right arbitration circuit CT (1) → CT (2) → CT (3)
→ CT (4) → CT (5) → CT (6) in the order of priority group A and the first access right arbitration circuit CT (7) → CT
(8) → CT (9) → CT (10) → CT (11) → CT (12) → CT
(13) → CT (14) → CT (15) → CT (16) in order of priority, divided into group B.

There is a priority boundary between the group A and the group B, that is, between the first access right arbitration circuit CT (6) and the first access right arbitration circuit CT (7). is there. Any of the first access right arbitration circuits CT (7) to CT (16) of the group B has a higher priority than any of the first access right arbitration circuits CT (1) to CT (6) of the group A. The access right arbitration circuit group G (3) and the access right arbitration circuit group G (3) consisting of the first access right arbitration circuits CT (7) to CT (16) belong to the access right arbitration circuit group G (3). First access right arbitration circuit CT (9)
CT (12) has a higher priority than the first access right arbitration circuits CT (13) to CT (16) of the access right arbitration circuit group G (4).

That is, the first access right arbitration circuits CT (1) to C (C) are arranged according to the boundary, the group type, and the arrangement order.
The priority order shown in the lower right frame of T (16) is shown.
This priority is given for convenience of explanation, and it is not necessary to know it in each of the first access right arbitration circuits CT (1) to CT (16).

In this way, when the 16 first access right arbitration circuits CT (1) to CT (16) are divided, the boundaries of the groups A and B are present in the ring arbiter RA1 (2), and the other rings. Arbiter RA1 (1), RA1 (3), RA1 (4)
Access right arbitration circuits CT (1) to CT (4) belonging to
, CT (9) to CT (12) and CT (13) to CT (16) belong to either group A or B. Each of the first access right arbitration circuits CT (1) to CT (16) recognizes only this group type. These Ring Arbiters RA1 (1)
In RA1 (4), at most one candidate is selected in one access opportunity, and if the candidate belongs to group A, the indicator data Ca is output, and if it belongs to group B, the indicator data Cb is output. . Therefore, the marker data Ca and Cb are not output at the same time. The marker data Ca and Cb are latched by the markers D1 to D4. For the markers D1 to D4, "0" is latched if the marker data Ca, and "1" is latched if the marker data Cb.

The access requests selected from the first access arbitration right circuit groups G (1) to G (4) are latched by the second access right arbitration circuits RAI (1) to RAI (4), respectively. It

In FIG. 1, "0" is latched in the indicators D1 and D2, and the first access right arbitration circuits CT (3) and G (1) having the access request of the first access right arbitration circuit group G (1). The first access right arbitration circuit CT (5) with the access request of (2) represents that it belongs to the group A. Further, "1" is latched in the indicators D3 and D4, and the first access right arbitration circuit CT (9) having the access request of the first access right arbitration circuit group G (3).
And the first access right arbitration circuit CT (14) with the access request of G (4) belongs to the group B.

The cyclic order of the ring arbiter RA2 is the second access right arbitration circuit RAI (1) → RAI (2) → RAI.
(3) → RAI (4). As a result, the access request latched in the second access right arbitration circuit RAI (3) has the highest priority.

The above operation will be described more specifically.
In the ring arbiter RA1 (1) consisting only of group A, the first access right arbitration circuit CT (1) at the head is given the first priority, and in the ring arbiter RA1 (2) consisting of groups A and B, At the boundary, the first access right arbitration circuit CT (7) belonging to the group B is given the first priority, and the ring arbiters RA1 (3) and RA1 (4) consisting of only the group B respectively have the first priority. First access right arbitration circuit CT (9) and CT (13)
Is given the highest priority.

Among these, if the first access right arbitration circuits CT (1) to CT (16) to which the access request is input are represented by ● marks, the priority order thereof is as follows in the ring arbiter RA1 (1). In the first access right arbitration circuit CT (3) and the ring arbiter RA1 (2), the first access right arbitration circuit CT (5) and in the ring arbiter RA1 (3) the first access right arbitration circuit CT. (9), Ring Arbiter RA1
In (4), the first access right arbitration circuit CT (14),
Becomes At the same time, the second access right arbitration circuit RAI
The marker data Ca or Cb is output to (1) to RAI (4), and the marker data Cb therein is latched by the markers D1 to D4. The content is the Ring Arbiter RA1
In (1), sign data Ca and ring arbiter RA
In 1 (2), sign data Ca and ring arbiter R
In A1 (3), it becomes labeling data Cb, and in ring arbiter RA1 (4), it becomes labeling data Cb. Therefore, the second access right arbitration circuits RAI (1) to RAI
In (4), the marker data Cb is latched in the markers 3 and 4, and the ring arbiter RA (2) is circulating from the left, so that the RAI (3) has the highest priority and is latched in it. The access request (ACK) is finally given to the access request of the first access right arbitration circuit CT (9).
The next boundary position is the first access right arbitration circuit CT (1).
~ CT (16), the first access right arbitration circuit CT
It is between (9) and CT (10).

As described above, according to this operation, the arbitration by the undivided large-scale ring arbiter in the conventional example has the same result, but since a plurality of access requests are processed in parallel at the same time, the access requests are processed. The competition arbitration time can be shortened.

Next, referring to FIG. 2, the output procedure of the marker data Ca and Cb in the first embodiment of the present invention will be described. FIG. 2 is a diagram showing an output procedure of marker data in the first embodiment of the present invention. This is a description of a portion corresponding to the access right arbitration circuit group G2 in FIG. 1. However, in order to make the description more understandable, here there are eight request generation sources R (1) to R (8). , Corresponding to 8
It is assumed that there are individual first access right arbitration circuits CT (1) to CT (8).

Each of the first access right arbitration circuits CT (1) to C
T (8) holds state values st (1) to st (8) indicating whether each belongs to group A or B. When the state value st (n) (1 ≦ n ≦ 8) holds the logical value “0”, the first access right arbitration circuit CT
(n) belongs to the group A, and when the state value st (n) holds the logical value "1", the first access right arbitration circuit CT (n) belongs to the group B.

Here, if the request source R (3) obtained the access right last time, the request source R (3) has the lowest priority this time. Therefore, the boundary between the group A and the group B is the first access right arbitration circuit CT (3).
And CT (4).

In FIG. 2, request generation sources R (2) and R (3)
, R (6) and R (7) generate access requests. The ring arbiter RA1 (k0) is the first access right arbitration circuit CT.
(1) to CT (8) are cycled, and the first access right arbitration circuit C of the request generation source R (6) having the highest priority is processed by the above-mentioned procedure.
Select T (6) as the first candidate.

In parallel with that, the ring arbiter RA1 (k0)
Controls the labeling data Ca or Cb. The ring arbiter RA1 (k0) is the first access right arbitration circuit CT (8).
To CT (1) from the beginning. At the start of this scanning, the marker data Ca is obtained. The first access right arbitration circuit CT (8) belongs to group B,
Although the logical value of the state value st (8) is "1", there is no access request here, the ring data arbiter RA1 (k0) remains the same as the indicator data Ca, and the next access right arbitration circuit C
Scan T (7). First access right arbitration circuit CT (7)
Has an access request, and the state value st (7) is the logical value "1", so the indicator data Ca is inverted to Cb. Since group B has priority,
Access right arbitration circuits CT (3) and CT belonging to
(2) also has an access request, but these are sign data Cb
Since it is not allowed to invert, the indicator data Cb
Is transmitted to the indicator D2 as it is, and further to the second access right arbitration circuit RAI (2) that the first candidate is the request generation source R (6).

As described above, in the device of the first embodiment of the present invention, contention arbitration of access requests is automatically performed.
In addition to the priority data that is automatically input to the indicators D1 to D4, data that affects the priority can be input in advance. That is, a fixed discrimination can be given to the priority order in advance by adding a prewritten data to the result of the automatic priority ordering as a new priority order.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram of the apparatus of the second embodiment of the present invention. In the apparatus of the second embodiment of the present invention, the second access right arbitration circuits CTa (1) to CTa (4) and CTb (1) to CTb.
(4) inherits the priority of the ring arbiter RA1 (1) to RA1 (4) and the information of the group A or B to which it belongs. Further, the indicators D1 to D4 hold a value of "0" or "1" for identifying the group A or B.

The ring arbiter RA2 is a second access right arbitration circuit CTa (1) to CTa (4), CTb (1) to CTb.
Patrol (4). The boundary of the ring arbiter RA2 is between the second access right arbitration circuits CTa (k) and CTb (k) corresponding to the ring arbiter RA1 (k) that obtained the previous access right. However, CTa (k) and CTb (k) are a pair, and the access permission obtained by either is given to the same RA1 (k).

In FIG. 3, the boundary of the ring arbiter RA2 is the second access right arbitration circuit CTa (2) and CTb.
It is between (2). Therefore, the second access right arbitration circuit C
Ta (1), CTb (1) and CTa (2) are in group A, and the second access right arbitration circuits CTb (2) and CTa (3) are included.
, CTb (3), CTa (4) and CTb (4) are group B
Becomes The cyclic order of the ring arbiter RA2 is the second access right arbitration circuit CTa (1) → CTb (1) → CTa (2) →
CTb (2) → CTa (3) → CTb (3) → CTa (4) → C
Tb (4) → CTa (1). The first candidate of group B has a higher priority than the first candidate of group A. This indicates that the first candidate selected from the ring arbiter RA1 (k) can be finally given access permission to one of the access requests by the ring arbiter RA2.

More specifically, the above operation will be described.
In the ring arbiter RA1 (1) consisting only of group A, the first access right arbitration circuit CT (1) at the head is given the first priority, and in the ring arbiter RA1 (2) consisting of groups A and B, At the boundary, the first access right arbitration circuit CT (7) belonging to the group B is given the first priority, and the ring arbiters RA1 (3) and RA1 (4) consisting of only the group B respectively have the first priority. First access right arbitration circuit CT (9) and CT (13)
Is given the highest priority.

Among them, if the first access right arbitration circuits CT (1) to CT (16) to which the access request is input are represented by ● marks, the priority order thereof is as follows in the ring arbiter RA1 (1). In the first access right arbitration circuit CT (3) and the ring arbiter RA1 (2), the first access right arbitration circuit CT (5) and in the ring arbiter RA1 (3) the first access right arbitration circuit CT. (9), Ring Arbiter RA1
In (4), the first access right arbitration circuit CT (14),
Becomes At the same time, the second access right arbitration circuit CTa
(1) to CTa (4) and CTb (1) to CTb (4) are output as the labeling data Ca or Cb. In the ring arbiter RA1 (1), the labeling data Ca and the ring arbiter RA1 are output. In (2), the labeling data Ca,
In the ring arbiter RA1 (3), the marker data C
In the ring arbiter RA1 (4) b, the tag data Cb. Therefore, of the second access right arbitration circuits CTa (1) to CTa (4) and CTb (1) to CTb (4), the second access right arbitration circuits CTa (1) and CTa (1)
Access requests are input to (2), CTb (3), and CTb (4), respectively. Second access right arbitration circuit CTa (1)
The priorities of CTa (4), CTb (1) to CTb (4) are located at the boundary, and the second access right arbitration circuit CTb (2) belonging to the group B is set as the first rank, and the second access is set thereafter. Power arbitration circuit CTa (3) → CTb (3) → CTa (4)
→ ... and the second access right arbitration circuit C
Since the indicator D3 of Tb (3) latches "1" and the second access right arbitration circuit CTb (3) belongs to the group B, it is input to the second access right arbitration circuit CTb (3). Access requests are selected. The ring arbiter RA1 (3) receives this selection information, and finally the first access right arbitration circuit CT (9) is given access permission.

The next boundary position is between the first access right arbitration circuits CT (9) and CT (10) in the first access right arbitration circuits CT (1) to CT (16). Second access right arbitration circuit CTa (1) -CTa (4), CTb (1)-
In CTb (4), the second access right arbitration circuit CT
It is between a (3) and CTb (3).

As described above, in the device of the second embodiment of the present invention, contention arbitration of access requests is automatically performed.
In addition to the priority data that is automatically input to the indicators D1 to D4, data that affects the priority can be input in advance. That is, a fixed discrimination can be given to the priority order in advance by adding a prewritten data to the result of the automatic priority ordering as a new priority order.

Next, with reference to FIG. 4, an output procedure of the marker data Ca and Cb in the second embodiment of the present invention will be described. FIG. 4 is a diagram showing an output procedure of marker data in the second embodiment of the present invention. In the second embodiment of the present invention, the acyclic ring arbiters c1, c2 and cb are used. The non-recursive ring arbiters c1 and c2 connect the groups A and B, scan from the first access right arbitration circuit CT (1) having the logical value “0” and the highest priority of the group A, and perform the non-cyclic. The ring arbiter c1 inverts the logical value in the first access right arbitration circuit CT (2) having the highest priority requesting access in the group A. The acyclic ring arbiter c2 inverts the logical value in the first access right arbitration circuit CT (6) having the highest priority requesting access in the group B.

That is, the first access right arbitration circuit CT (n) whose logical values are inverted by the acyclic ring arbiters c1 and c2 is the first candidate spare candidate selected in the group A or B, respectively. Is. Therefore, there are at most two preliminary candidates.

Further, the acyclic ring arbiter cb starts scanning from the first access right arbitration circuit CT (8), and has a state value st (n) having an access request from the first access right arbitration circuit CT (n). ) Is "1", the acyclic ring arbiter cb has a logical value of "1".
Since the presence / absence of the access request from the group B is transmitted to the group A, the backup candidate of the group A is canceled when the access request is to the group B, and the access request of the backup candidate of the group B by the non-cyclic ring arbiter c2 is transmitted. Become a candidate.

In FIG. 4, request generation sources R (2) and R (3)
, R (6), R (7) generate an access request, the acyclic ring arbiter c1 starts scanning from the first access right arbitration circuit CT (1), and the logical value of the state value st (2) Is "0", the logical value of the non-cyclic ring arbiter c1 is "1". The non-cyclic ring arbiter c2 starts scanning from the first access right arbitration circuit CT (1), and the state value s
Since the logical value of t (6) is "1", the logical value of the non-cyclic ring arbiter c2 is set to "1". As a result, the first access right arbitration circuit CT (2) becomes a preliminary candidate for group A, The first access right arbitration circuit CT (6) is a preliminary candidate for the group B, and the non-cyclic ring arbiter cb starts scanning from the first access right arbitration circuit CT (8). Since the logical value of the state value st (7) of the circuit CT (7) is "1", the logical value of the acyclic ring arbiter cb is set to "1". Group A reserve candidate is canceled because it is transmitted to the non-cyclic ring arbiter c.
The access request of the preliminary candidate of the group B by 2 becomes the first candidate.

An advantage of the second embodiment of the present invention is that by using the non-cyclic ring arbiters c1, c2, cb in parallel, the arbitration time can be doubled as compared with the cyclic ring arbiter. is there.

Next, the operation of the first and second embodiments of the present invention will be described in more detail with reference to FIG. FIG. 5 is a diagram showing operations in the access right arbitration circuit groups G (1) to G (3). In the access right arbitration circuit group G (1), at the point A, the acyclic ring arbiter c1 confirms the access request and flips it from "0" to "1". Since the acyclic ring arbiter c2 has no access request belonging to the group B, the scanning is terminated with "0". Since the non-cyclic ring arbiter cb also has no access request belonging to the group B, the scan is ended with "0". The candidate and the marker data Ca at the point A belonging to the group A are output.

In the access right arbitration circuit group G (2), since the non-cyclic ring arbiter c1 has no access request belonging to the group A, the scanning is terminated with "0". At the point B, the acyclic ring arbiter c2 confirms the access request existing in the group B and reverses the access request from "0" to "1". The non-recursive ring arbiter cb is point C
At, the access request existing in the group B is confirmed and it is inverted from "0" to "1". The candidate at the point B belonging to the group B and the marker data Cb are output.

In the access right arbitration circuit group G (3), since the non-cyclic ring arbiter c1 has no access request belonging to the group A, the scanning is terminated with "0". At the point D, the acyclic ring arbiter c2 confirms the access request existing in the group B and inverts it from "0" to "1". The non-cyclic ring arbiter cb is point E
At, the access request existing in the group B is confirmed and it is inverted from "0" to "1". The candidate at the point D belonging to the group B and the marker data Cb are output.

These three access right arbitration circuit groups G
In (1) to G (3), the access request at the point B has the highest priority as a candidate belonging to the group B closest to the boundary.

In the first and second embodiments of the present invention, the number of the request generation sources R (1) to R (16) is determined and explained, but the number can be configured arbitrarily.

Although the above description has been made assuming that there is hardware called a ring arbiter, a practical design can be executed by a logical operation developed on the memory area by the program control circuit.

Returning to FIG. 7, the above description is based on the resource S (1).
Is a description of one row of a matrix connected to
A network as shown in FIG. 7 can be configured by using a plurality of these columns. In addition, the request generation sources R (1) to R
The number of (8) and the resources S (1) to S (8) can be arbitrarily configured, but in reality, they are tens or hundreds.

[0058]

As described above, according to the present invention, the access request search can be divided into a plurality of parts and processed in parallel, so that the contention arbitration time can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a diagram showing an output procedure of marker data in the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a second embodiment of the present invention.

FIG. 4 is a diagram showing an output procedure of marker data in the second embodiment of the present invention.

FIG. 5 is a diagram showing the operation of the first and second embodiments of the present invention.

FIG. 6 is a conceptual diagram illustrating the operation of a ring arbiter.

FIG. 7 is a diagram showing a network configuration.

[Explanation of symbols]

D1 to D4 Marks A to E Points R (1) to R (16) Request source RA1 (1) to RA1 (4), RA1 (k), RA1 (ko), R
A2 Ring arbiter S (1), S (m) Resources CT (1) -CT (16) First access right arbitration circuits CTa (1) -CTa (4), CTa (k), CTb (1) -C
Tb (4), CTb (k), RAI (1) to RAI (4) Second access right arbitration circuit OR (1) to OR (4) OR gate circuit G (1) to G (4) Access right arbitration Circuit group A, B group Ca, Cb Indicator data st (1) -st (8) State values c1, c2, cb Non-cyclic ring arbiter

Continuation of front page (56) Reference JP-A-6-104916 (JP, A) JP-A-3-241434 (JP, A) JP-A-4-102155 (JP, A) JP-A-4-96165 (JP , A) JP-A-56-72752 (JP, A) JP-A-5-191424 (JP, A) Proposal of competitive control method for ultra-high-speed ATM switch, 1992 IEICE Spring Conference B-451, 1992 March 15, 2013 Study on ultra-high speed ATM switch architecture, IEICE Technical Report SSE91-157, March 5, 1992 (58) Fields investigated (Int.Cl. ⁷ , DB name) G06F 13 / 362 510 H04L 12/28

Claims (3)

(57) [Claims] 1. An access request generated from a plurality of N request generation sources is selected one by one for each time slot.
In an access arbitration device that gives access rights to one resource shared by a plurality of access request sources, the N request generation sources are arranged in the access request selection order.
Therefore , the priority of the access request source that has been arranged in a single line and has obtained the access right immediately before that is lowered to the lowest priority.
As a matter of fact, the access request source that fell to the bottom of the
It is assumed that a virtual boundary line is set later, and the N number of first request sources provided corresponding to the N number of request generation sources are set.
Access right arbitration circuit and the N first access right arbitration circuits
Keep the order in which N request sources are arranged in a row
Divide into multiple groups, and each group
Select the highest priority access request for each slot
And a second access right arbitration circuit that receives an access request for each group selected by the first ring arbiter.
And a second ring arbiter that selects one access request for each time slot from the second access right arbitration circuit.
And a motor, said N first access arbitration circuit corresponding request
Whether the source is upstream or downstream of the virtual boundary line
The second access right arbitration circuit recognizes a sign that is information of
First selected by the first ring arbiter with request
The second ring arbiter receives the sign recognized by the access right arbitration circuit of the
One access request from the highest priority group
Only selected, the first ring arbiter and second Ringuabi
Access right arbitration circuit in the
The access right arbitration circuit is selected by the access right arbitration
Circuits with downstream markings have higher priority
Then, the label has the same access rights arbitration circuit there is more place
If the access right arbitration circuit is located upstream,
An access arbitration device characterized by performing as a high-ranking item . 2. The access arbitration apparatus according to claim 1, wherein the first ring arbiter includes means for cyclically scanning request generation sources in the group in the order of arrangement. 3. The access arbitration according to claim 1, wherein the first ring arbiter includes means for scanning request sources in the group in parallel from start point to end point and from end point to start point according to the arrangement. apparatus.