JP2003271545A - Data processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data processing system having a bus mediation device 6 enabling application to an arbitrary application without creating a number of priority tables. <P>SOLUTION: In the data processing system having a bus mediation device 6 for mediating bus access to a shared bus in a plurality of modules, the plurality of modules and a control part are connected to a shared bus. The bus mediation device 6 has group setting means 16, 17 for allocating the plurality of modules to one of a plurality of mediation groups, intra-group mediation means 18(1) to 18(M) for mediating a bus access to the shared bus in each of the plurality of mediation groups, an inter-group mediation means 19 for mediating a bus access to the shared bus between the plurality of mediation groups, and a bus use enable signal generating part 20 for feeding a bus use enable signal ack1 to ackN to the module mediated by the inter-group mediation means 19. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing system, and more particularly, to a bus arbitration device in which a plurality of modules and a control unit are connected to a shared bus to arbitrate bus access to the shared bus in the plurality of modules. The present invention relates to a data processing system including.

[0002]

2. Description of the Related Art Recently, in a data processing system or the like, a system LSI in which a constituent part including a plurality of modules is integrally configured in a one-chip large-scale integrated circuit (LSI) is widely used. In this case, the modules
The applied applications may differ from each other, and if an arbitrary application is applied to such a system LSI, the access priority to the shared bus in the plurality of modules will be different.
Therefore, in the system LSI, it is necessary to set the access priority to the shared bus that is optimal for application of an arbitrary application.

A conventional bus arbitration device used in a data processing system or the like is, for example, Japanese Patent Laid-Open No. 2000-2679.
A DMA controller disclosed in No. 93 is known. This D
The MA control device includes a device monitor unit that detects whether or not a plurality of modules are accessing the bus, and a plurality of different priority tables that record bus access priorities among the plurality of modules. The priority table to be used is switched according to the detection result. In this case, the priority table used is a table in which the bus access priorities of a plurality of modules are fixedly determined in advance.

FIG. 17 shows the above-mentioned Japanese Unexamined Patent Publication No. 2000-26799.
FIG. 4 is a block diagram showing a main configuration of a DMA control device disclosed in No. 3;

As shown in FIG. 17, this DMA control device comprises a device monitor unit 71 and a bus arbitration unit 72, and the bus arbitration unit 72 has a first priority table (priority table 1) 73 (1). ) And a second priority table (priority table 2) 73 (2), and a bus response control section 74.

The DMA control device (bus arbitration device) having the above-described structure operates as follows.

Multiple (N) modules (not shown)
Generates a device status signal indicating whether or not the bus is currently accessed for each module, supplies the device status signals to the device monitor unit 71, and generates bus use request signals req1 to N for each module. Then, the bus use request signals req1 to N are sent to the bus arbitration unit 72.
Supply to. Upon receiving the device status signals from the plurality of modules, the device monitor unit 71 generates a priority table selection signal for selecting an optimum priority table according to the device status signals, and outputs the priority table selection signal to the bus. It is supplied to the arbitration unit 72. Bus arbitration unit 7
2, when the priority table selection unit 73 receives the priority table selection signal, the priority table instructed by the priority table selection signal, for example, the first priority table 73 (1) is selected and selected. The bus use request signals req1 to N are selected according to the priority order of the first priority order table 73 (1), and the selected bus use request signal, for example, the bus use request signal req1 is supplied to the bus response control unit 74. The bus response control unit 74 generates the bus use permission signals ack1 to N based on the supplied bus use request signal req1 and supplies the obtained bus use permission signal, for example, ack1 to the corresponding module.

[0008]

When the bus arbitration device is applied to an arbitrary application, the known bus arbitration device needs to newly create a priority table optimum for the application to be applied each time. It takes a considerable amount of time and effort to newly create such a priority table. On the other hand, in order to avoid creating a new priority table, it is possible to create a priority table applicable to all expected applications in advance, but suppose that the number of modules used in the system is N. , N factorial priority tables must be created, and the number of priority tables created is huge, especially when the number of modules used in the system is large. The number of priority tables also increases accordingly.

Further, in the data processing system, when data processing using a shared bus by a plurality of modules is performed and this data processing is executed by a task, it is possible to quickly execute bus access for a task having a high priority. Required. However, since the known bus arbitration device selects the priority table by a signal depending on the device status indicating whether or not a plurality of modules are currently accessing the bus, the priority of the bus access is given regardless of the priority of the task. However, it is not possible to satisfy the demand that the bus access of the task having the high priority is executed promptly.

The present invention has been made in view of the above technical background, and its first object is to make it possible to apply it to any application without creating a large number of priority tables. Another object of the present invention is to provide a data processing system having the bus arbitration device.

A second object of the present invention is to provide a data processing system having a bus arbitration device capable of promptly executing bus access for a task having a high priority when data processing is executed by a task. To provide.

[0012]

In order to achieve the first object, the present invention provides a shared bus in which a plurality of modules and a control unit are connected to arbitrate bus access to the shared bus in the plurality of modules. In the data processing system including the bus arbitration device that performs the above, the bus arbitration device includes a group setting unit that assigns and sets a plurality of modules to one of a plurality of arbitration groups, and a bus access control for a shared bus for each of the plurality of arbitration groups. Intra-group arbitration means for arbitrating, inter-group arbitration means for arbitrating bus access to the shared bus among a plurality of arbitration groups, and bus use for supplying a bus use permission signal to a module arbitrated by the inter-group arbitration means And a permission signal generator.

According to the first means, the bus arbitration device includes a group setting means, an intra-group arbitration means, an inter-group arbitration means, and a bus use permission signal generating section, and the group setting means allows a plurality of modules to operate in a plurality of modules. Allocate to one of the arbitration groups and perform arbitration processing based on the bus usage request for each arbitration group set by the arbitration means within the group, and then perform arbitration processing between the arbitration groups by the arbitration means between groups to access the bus. The bus enable signal is supplied to the selected module by the bus enable signal generation unit by selecting the module to be enabled, so the bus arbitration optimal for any application can be performed without creating many priority tables. The priority of can be set.

In order to achieve the first object,
The present invention is a data processing system comprising a bus arbitration device in which a plurality of modules and a control unit are connected to a shared bus, and which arbitrates bus access to the shared bus in the plurality of modules. Group setting means for assigning and setting the module of one of the arbitration groups to any of the arbitration groups, arbitration means within the group for arbitrating bus access to the shared bus for each arbitration group, and arbitration method between the arbitration groups Inter-group arbitration means for arbitrating inter-group arbitration setting means, arbitration of bus access to a shared bus among a plurality of arbitration groups by the arbitration method set by inter-group arbitration setting means, and arbitration by inter-group arbitration means A second hand having a bus use permission signal generator for supplying the bus use permission signal to the module Comprising a.

According to the second means, the bus arbitration device includes the group setting means, the intra-group arbitration means, the inter-group arbitration setting means, the inter-group arbitration means, and the bus use permission signal generating section, and the group setting means Assign multiple modules to one of multiple arbitration groups,
Arbitration processing is performed based on the bus use request for each arbitration group set by the intra-group arbitration means, the inter-group arbitration setting means sets the arbitration method between a plurality of arbitration groups, and then the inter-group arbitration means sets the arbitration groups. Since the arbitration process is performed according to the set arbitration method, the module that permits bus access is selected, and the bus use permission signal is supplied to the selected module by the bus use permission signal generation unit. It is possible to set the optimum bus arbitration priority for an arbitrary application and perform the bus arbitration by the optimum arbitration method without creating the.

Further, in order to achieve the second object, the priority of the task when the plurality of modules in the first and second means perform data processing is the priority of the bus access to the shared bus. Third set correspondingly
It is equipped with means.

According to the third means, the priorities of tasks when a plurality of modules perform data processing are set in accordance with the priorities of bus access to the shared bus. Bus access to high tasks can be set preferentially, and high-priority tasks can be executed quickly.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the main configuration of a data processing system according to the present invention.

As shown in FIG. 1, the data processing system includes a data processing device 1 and a control unit (CPU) 2.
And a storage unit (memory) 3, a display unit 4, and a hard disk (HD) 5. Further, the data processing device 1 is
Bus arbitration device 6 and control unit interface unit (CPU
I / F section) 7, memory controller section 8, drawing processing section 9, display control section 10, hard disk control section (HD control section) 11, video input control section 12, and audio input control section 13. The communication control unit 14 and the shared bus 15 are included. In this case, the drawing processing unit 9, the display control unit 10, the hard disk control unit 11, the video input control unit 12, the audio input control unit 13, and the communication control unit 14 each constitute a module.

In the data processing device 1, the bus arbitration device 6 includes a control unit interface unit 7, a memory controller unit 8, a drawing processing unit 9, a display control unit 10, a hard disk control unit 11, a video input control unit 12, and an audio. It is connected to the input control unit 13 and the communication control unit 14, respectively, and is also connected to the control unit 2. The control unit interface unit 7 is
It is connected to the shared bus 15 and is also connected to the control unit 2. The memory controller unit 8 is connected to the shared bus 15 and also connected to the storage unit 3. The drawing processing unit 9 is connected to the shared bus 15. The display control unit 10 is connected to the shared bus 15 and is also connected to the display unit 4. Hard disk controller 1
1 is connected to the shared bus 15 and is also connected to the hard disk 5. Video input control unit 12, audio input control unit 1
3. The communication control unit 14 is connected to the shared bus 15, respectively.

In this data processing system, the control unit interface unit 7, the memory controller unit 8, the drawing processing unit 9, the display control unit 10 and the hard disk are controlled by the control unit 2 and according to the arbitration processing by the bus arbitration device 6. Time-divisional data transmission using the shared bus 15 is performed among any of the control unit 11, the video input control unit 12, the audio input control unit 13, and the communication control unit 14. The arbitration process performed by the bus arbitration device 6 will be described later.

Next, FIG. 2 shows a first embodiment of the bus arbitration device 6 used in the data processing system shown in FIG. 1, and is a block diagram showing a main part configuration thereof.

As shown in FIG. 2, the bus arbitration device 6 includes a group setting unit 16, a bus use request signal selection unit 17, and a first intra-group arbitration unit (group 1) 18.
(1) and the second intra-group arbitration unit (group 2) 18
(2) and the M-th intra-group arbitration unit (group M) 18
(M), an inter-group arbitration unit 19, a bus use permission signal generation unit 20, a bus use request signal input terminal 21, and a bus use permission signal output terminal 22.

Then, the bus use request signal selecting section 17 is
Group setting unit 16, bus use request signal input terminal 21, first intra-group arbitration unit 18 (1), second intra-group arbitration unit 18 (2), and M-th intra-group arbitration unit 18
(M), respectively. The first intra-group arbitration unit 18 (1) is connected to the inter-group arbitration unit 19 and the bus use permission signal output terminal 22, respectively. The second intra-group arbitration unit 18 (2) is connected to the inter-group arbitration unit 19 and the bus use permission signal output terminal 22, respectively. The M-th intra-group arbitration unit 18 (M) is an inter-group arbitration unit 19
And a bus use permission signal output terminal 22 are respectively connected. The inter-group arbitration unit 19 is the bus use permission signal generation unit 2
0, and the bus use permission signal generator 20 is connected to the bus use permission signal output terminal 22.

In this case, the bus use request signal input terminal 21
Includes a plurality of modules, such as the drawing processing unit 9, the display control unit 10, and the hard disk control unit 1 shown in FIG.
1, bus input request signals req1 to N from the video input control unit 12, the audio input control unit 13, the communication control unit 14, etc., respectively.
Is supplied. The bus use request signal selection unit 17 outputs the bus use request signals req1s1 to Ns1 to the first intra-group arbitration unit 18 (1), and the second intra-group arbitration unit 18
For (2), bus use request signals req1s2 to Ns2
And the bus use request signals req1sM to NsM are respectively supplied to the M-th intra-group arbitration unit 18 (M).
The first intra-group arbitration unit 18 (1) instructs the inter-group arbitration unit 19 to use the bus use request signals req1g1 to Ng1.
The second intra-group arbitration unit 18 (2) sends the bus use request signals req1g2 to N to the inter-group arbitration unit 19.
g2, and the M-th intra-group arbitration unit 18 (M) sends the bus use request signal req1gM to the inter-group arbitration unit 19.
~ NgM respectively. Inter-group mediation section 19
Is a bus use request signal r to the bus use permission signal generator 20.
eq1a to Na are supplied. Bus use permission signal generator 2
0 supplies the bus use permission signals ack1 to N to the selected module through the bus use permission signal output terminal 22.

The bus arbitration device 6 having the above structure operates as follows.

The group setting unit 16 has a built-in group setting register, and the group setting register stores a group value indicating an arbitration group corresponding to the bus use request signals req1 to N under the control of the control unit 2. Is supplied to the bus use request signal selection unit 17 as a group setting signal. Bus use request signal selector 1
7 assigns the bus use request signals req1 to N supplied from a plurality of modules based on the group setting signal supplied from the group setting unit 16, and sets the bus to the first intra-group arbitration unit 18 (1). Usage request signal req1g
1 to Ng1, the second intra-group arbitration unit 18 (2) to the bus use request signals req1g2 to Ng2, and the Mth intra-group arbitration unit 18 (M) bus use request signal req1gM to
NgM is supplied respectively. In this case, one of the bus use request signals req1 to N, for example req1, is supplied to only one intra-group arbitration unit, for example, the first intra-group arbitration unit 18 (1).
It is not supplied to each of the three or three group arbitration units.

The first intra-group arbitration unit 18 (1) supplies the bus use request signals req1s1 to Ns1 supplied from the bus use request signal selection unit 17 and the bus use permission signal supplied from the bus use permission signal generation unit 20. Arbitration processing is performed based on the signals ack1 to N, and the arbitrated bus use permission signal re
q1g1 to Ng1 are supplied to the inter-group arbitration unit 19.
Similarly, the second intra-group arbitration unit 18 (2) receives the bus use request signals req1s2 to Ns2 supplied from the bus use request signal selection unit 17 and the bus use permission signal generation unit 20.
Arbitration processing is performed on the basis of the bus use permission signals ack1 to N supplied from
g2 to Ng2 are supplied to the inter-group arbitration unit 19, and the M-th intra-group arbitration unit 18 (M) supplies the bus use request signal req1sM to the bus use request signal selection unit 17 supplied from the bus use request signal selection unit 17.
Arbitration processing is performed based on NsM and the bus use permission signals ack1 to N supplied from the bus use permission signal generation unit 20, and the arbitrated bus use permission signals req1gM to NgM are supplied to the inter-group arbitration unit 19.

The inter-group arbitration unit 19 uses the bus use permission signal r supplied from the first intra-group arbitration unit 18 (1).
eq1g1 to Ng1, second intra-group arbitration unit 18
Bus use permission signal req1s2 supplied from (2)
Ns2, inter-group arbitration is performed based on the bus use permission signals req1sM to NsM supplied from the M-th intra-group arbitration unit 18 (M), and the arbitrated bus use request signal re
The signals q1a to Na are supplied to the bus use permission signal generator 20. The bus use permission signal generator 20 receives the bus use request signals req1a to Na supplied from the inter-group arbitration unit 19.
Based on the above, the bus use permission signals ack1 to N are output to the module which permits the bus access this time.

Next, FIG. 3 is an explanatory diagram showing an example of the group set values stored in the group setting register built in the group setting section 16 shown in FIG.

As shown in FIG. 3, in this group setting value example, the bus use request signal req1 and the bus use request signal req2 are in the group 1 and the bus use request signal req is in the group 1.
q3 and the bus use request signal req4 are set to the group 2, and the bus use request signal reqN is set to the group M.

Next, FIG. 4 is a block diagram showing an example of the configuration of the first intra-group arbitration unit 18 (1) shown in FIG.

As shown in FIG. 4, the first intra-group arbitration unit 18 (1) includes a previous access storage unit 23, a round robin table 24, a bus use request signal input terminal 25, and a bus use permission signal. It comprises an input terminal 26 and a bus use request signal output terminal 27.

The previous access storage unit 23 includes the round robin table 24 and the bus use permission signal input terminal 2
6 is connected. The round robin table 24 is connected to the bus use request signal input terminal 25 and the bus use request signal output terminal 27.

In this case, the previous access storage unit 23 stores the module that accessed the bus last time and outputs the previous access signal.
4 is for performing round robin arbitration. Round-robin arbitration is a bus arbitration method that, when bus usage requests are simultaneously issued from multiple modules, the module that accessed the bus immediately before is given the lowest priority and the next bus arbitration is performed. Bus arbitration can be realized.

Here, FIG. 5 is an explanatory view showing an example of the stored contents of the round robin table 24 shown in FIG. 4, and shows an example in which the number of modules N is four.

The operation of the first intra-group arbitration unit 18 (1) shown in FIG. 4 will be described based on the stored contents of the round robin table 24 shown in FIG.

In the first intra-group arbitration unit 18 (1), the previous access signal output from the previous access storage unit 23 is the module 4 (req4s1), and the bus use request signal input terminal 25 supplies the bus use signal. From the request signals req1s1 to 4s1, the current bus use request is module 1 (req1s1), module 2 (req2s).
1), module 3 (req3s1), module 4
If it is output from (req4s1), the module 1 (re
q1s1) is the bus use request signal having the highest priority, and the bus use request signal req1g1 is output through the bus use request signal output terminal 27. At this time, when the bus use permission signal generator 20 shown in FIG. 2 forms the bus use permission signal ack1 for the module 1, the module 1 is stored in the previous access storage unit 23.

Next, the current bus use request is module 1
(Req1s1), module 2 (req2s1), module 3 (req3s1), module 4 (req4
s1), the module 2 (req2s1) is determined to be the bus use request signal with the highest priority according to the round robin table 24, and the bus use request signal req2 is output through the bus use request signal output terminal 27.
g1 is output. At this time, the bus use permission signal generator 20 outputs the bus use permission signal ack2 to the module 2.
Is formed, the module 2 is stored in the previous access storage unit 23.

Next, the current bus use request is module 1 (req1s1), module 2 (req2s1),
Module 3 (req3s1), Module 4 (req
4s1), the module 3 (req3s1) is determined to be the bus use request signal having the highest priority according to the round robin table 24, and the bus use request signal req is output through the bus use request signal output terminal 27.
3g1 is output. At this time, the bus use permission signal generator 20 outputs the bus use permission signal ack to the module 3.
When 3 is formed, the module 3 is stored in the previous access storage unit 23.

Similarly, the current bus use request is module 1 (req1s1), module 2 (req2s1),
Module 3 (req3s1), Module 4 (req
4s1), the module 4 (req4s1) is determined to be the bus use request signal having the highest priority according to the round robin table 24, and the bus use request signal req is output through the bus use request signal output terminal 27.
4g1 is output. At this time, the bus use permission signal generator 20 outputs the bus use permission signal ack to the module 4.
When 4 is formed, the module 4 is stored in the previous access storage unit 23.

Thus, the first intra-group arbitration unit 18
According to (1), even if several bus use requests occur at the same time, it is possible to equally arbitrate the buses for the modules 1 to 4. In addition, the second intra-group arbitration unit 18 (2) and the M-th intra-group arbitration unit 18
Also in (M), the first intra-group arbitration unit 18 (1)
The same operation is executed as the operation executed in.

FIG. 6 is an explanatory diagram showing an example of the stored contents stored in the internal table of the inter-group arbitration unit 19 shown in FIG.

As shown in FIG. 6, the internal table of the inter-group arbitration unit 19 stores arbitration contents for performing fixed priority arbitration. In this case, the fixed-priority arbitration is a method in which fixed priorities of input bus use request signals are fixed in advance and arbitration is performed in accordance with the priorities.

The operation of the inter-group arbitration unit 19 will be described based on the stored contents shown in FIG. In this description, the group setting unit 16 shown in FIG.
, The bus use request signal req1 and the bus use request signal req2 are assigned to the group 1, and the bus use request signal req is
3 and the bus use request signal req4 are set to the group 2.

Now, the first intra-group arbitration unit 18 (1)
Outputs either the bus use request signal req1g1 or the bus use request signal req2g1 as an arbitrated bus use request signal from the second intra-group arbitration unit 18
From (2), either the bus use request signal req3g2 or the bus use request signal req4g2 is output as the arbitrated bus use request signal. If no bus use request is generated from each of the modules 1 to 4, the bus use request signal after arbitration is not generated.

At this time, the first intra-group arbitration unit 18
The bus use request signal arbitrated in (1) is req1g1,
When the bus use request signal arbitrated by the second intra-group arbitration unit 18 (2) is req3g2, the bus use request signal req1g1 is the most between the two groups according to the fixed priority arbitration of the built-in table shown in FIG. It is determined that the bus use request signal has a high priority, and the inter-group arbitration unit 19 outputs the bus use request signal req1a. On the other hand, the bus use request signal is not generated in the first intra-group arbitration unit 18 (1), and the bus use request signal arbitrated in the second intra-group arbitration unit 18 (2) is req.
4g2, the bus use request signal req4g2 is determined to be the bus use request signal having the highest priority between the two groups according to the fixed priority arbitration of the built-in table,
Bus use request signal req4a from inter-group arbitration unit 19
Is output.

As described above, in the inter-group arbitration unit 19, the bus use request signal re arbitrated between the groups is
Fixed priority arbitration is performed on q1g1 to Ng1 and req1g2 to Ng2. By performing such arbitration, for example, a bus use request of a module that requires real-time processing is given a higher priority (group 1 in the example of FIG. 6), so that the module has a higher priority than other modules. Bus access can be executed preferentially.

FIG. 7 is a flow chart showing the operation history of the bus arbitration device 6 shown in FIG.

The operation of the bus arbitration device 6 will be described based on the flow chart shown in FIG.

First, in step S1, the control unit 2
Under the control of, the group setting value is written and set in the group setting register built in the group setting unit 16, and the group to which the bus use request signals req1 to N are assigned and set is determined.

Next, in step S2, it is determined whether or not a bus use request is issued from a plurality of modules. When it is determined that the bus use request is generated (Y), the process proceeds to the next step S3, while when it is determined that the bus use request is not generated (N), this step S2 is repeatedly executed. To do.

Next, in step S3, the bus use request signal selection unit 17 follows the group use signal supplied from the group setting unit 16 and uses the bus use request signal req1.
s1 to Ns1 to the first intra-group arbitration unit 18 (1),
The bus use request signals req1s2 to Ns2 are sent to the second intra-group arbitration unit 18 (2).
Each of M to NsM is output to the M-th intra-group arbitration unit 18 (M).

Then, in step S4, the first intra-group arbitration unit 18 (1) and the second intra-group arbitration unit 1
8 (2), the bus use request signals req1s1 to Ns1, re in the M-th intra-group arbitration unit 18 (M), respectively.
Arbitration processing based on q1s2 to Ns2 and req1sM to NsM is performed. The intra-group arbitration method in this case is as described in FIGS. 4 and 5.

In step S5, the bus use request signal having the highest priority in each of the first to Mth groups, that is, the bus use request signals req1g1 to 1q1 in the first intra-group arbitration unit 18 (1). Any one of Ng1 and one of the bus use request signals req1g2 to Ng2 in the second intra-group arbitration unit 18 (2), req1gM to Mq in the Mth intra-group arbitration unit 18 (M). Any one of NgM is output to the inter-group arbitration unit 19.

Next, in step S6, the inter-group arbitration unit 19 performs arbitration processing on the bus use request signals supplied from the first to Mth groups. The inter-group arbitration method in this case is as described in FIG.

Next, in step S7, the bus use request signals req1a-Na having the highest priority and arbitrated by the inter-group arbitration unit 19 are output to the bus use permission signal generation unit 20.

Subsequently, in step S8, the bus use permission signal generator 20 selects each of the first to Mth groups based on the bus use request signals req1a to Na output from the inter-group arbitration unit 19. The bus use permission signals ack1 to N are output to the module. After this processing is performed, the process returns to step S2, and every time a bus use request is issued from each of the first to Mth modules, step S2 is performed.
The operations after 2 are repeatedly executed.

Next, FIG. 8 is a time chart showing an example of the adjustment timing at the time of the bus arbitration processing performed by the bus arbitration device 6 shown in FIG. This time chart shows the bus use request signal req1 and the bus use request signal r.
eq2 is set to group 1, bus use request signal req3 and bus use request signal req4 are set to group 2, round robin arbitration is performed for intragroup arbitration, and intergroup arbitration is fixed priority. This is when arbitration is performed.

Using the time chart shown in FIG.
The operation of the bus arbitration device 6 will be described. However, in this explanation, last time, the first intra-group arbitration unit 18
It is assumed that the module 2 (req2) is bus-accessed in (1) and the module 4 (req4) is bus-accessed in the second intra-group arbitration unit 18 (2).

First, at time t0, the bus use request signals req1, req2, req3, req4 are simultaneously generated. In this case, the arbitration process is performed according to the flowchart shown in FIG. That is, the bus use request signals req1g1 to Ng1 output from the first intra-group arbitration unit 18 (1) are the bus use request signals req1 output from the second intra-group arbitration unit 18 (2).
g2 to Ng2 have a higher priority, and last time, in the first intra-group arbitration unit 18 (1), the module 2 (req
Since the bus access in 2) is being performed, module 1
(Req1) is the bus use request signal having the highest priority.

Next, at time t1, the bus use permission signal ack1 is output in response to the arbitrated bus use request signal req1g1.

Next, at time t3, the bus use request signals req1g1 to Ng1 output from the first intra-group arbitration unit 18 (1) are output from the second intra-group arbitration unit 18 (2). Bus use request signal req1g
2 to Ng2, the module 1 (req has a higher priority than the module 1 (req) in the first intra-group arbitration unit 18 (1) last time.
Since the bus access of 1) is being performed, module 2
(Req2) is the bus use request signal having the highest priority.

Subsequently, at time t4, the bus use permission signal ack2 is output in response to the arbitrated bus use request signal req1g2.

At time t6, since the bus use request signal is not generated from the modules 1 and 2 of the first intra-group arbitration unit 18 (1), the second intra-group arbitration unit 18 (2) is generated. Bus use request signal req output from
The bus use request signal having the highest priority is selected from 1g2 to Ng2. In this case, the second intra-group arbitration unit 18
In (2), since the bus access of module 4 (req4) was performed last time, module 3 (req3)
Is the bus use request signal with the highest priority.

Next, at time t7, the bus use permission signal ack3 is output in response to the arbitrated bus use request signal req3g2.

Next, at time t9, since the bus use request signal is not generated from the modules 1 and 2 of the first intra-group arbitration unit 18 (1), the second intra-group arbitration unit 18 (2) is generated. Bus use request signal re output from
The bus use request signal having the highest priority is selected from q1g2 to Ng2. In this case, the second intra-group arbitration unit 1
In 8 (2), the bus access of the module 3 (req3) was performed last time, so the module 4 (req4)
Is the bus use request signal with the highest priority.

Subsequently, at time t10, the bus use permission signal ack4 is output in response to the arbitrated bus use request signal req4g2.

As described above, in the bus arbitration device 6 shown in FIG. 2, the round robin arbitration is performed within the group, the fixed priority arbitration is performed between the groups, and the selected modules 1 to 4 are selected. The bus use permission is output to the output.

Next, FIG. 9 shows a second embodiment of the bus arbitration device 6 used in the data processing system shown in FIG. 1, and is a block diagram showing the configuration of the main part thereof.
The same components as those shown in FIG. 2 are designated by the same reference numerals.

The bus arbitration device 6 according to the second embodiment (hereinafter referred to as the second bus arbitration device 6) is the bus arbitration device 6 according to the first embodiment (hereinafter referred to as the first bus arbitration device 6). Compared with the bus arbitration device 6), it has the same basic configuration but is different in the following points. That is, the second bus arbitration device 6 is provided with the inter-group arbitration setting unit 28, which is not included in the first bus arbitration device 6, and the second bus arbitration device 6 is provided in the inter-group arbitration unit 19. While the bus use permission signals ack1 to N are configured to be supplied, the first bus arbitration device 6 is
First intra-group arbitration unit 18 (1), second intra-group arbitration unit 18 (2), M-th intra-group arbitration unit 18 (M)
Are configured to be supplied with the bus use permission signals ack1 to N, respectively, and the other points are configured between the first bus arbitration device 6 and the second bus arbitration device 6. There is no difference above. In this case, the inter-group arbitration setting unit 2
8 supplies an inter-group arbitration setting signal to the inter-group arbitration unit 19 as described later.

Second bus arbitration device 6 having such a configuration
Works as follows:

The group setting unit 16 has a built-in group setting register, and the group setting register stores the group value indicating the arbitration group corresponding to the bus use request signals req1 to N under the control of the control unit 2. Is supplied to the bus use request signal selection unit 17 as a group setting signal. Bus use request signal selector 1
7 assigns the bus use request signals req1 to N supplied from a plurality of modules based on the group setting signal supplied from the group setting unit 16, and sets the bus to the first intra-group arbitration unit 18 (1). Usage request signal req1g
1 to Ng1, the second intra-group arbitration unit 18 (2) to the bus use request signals req1g2 to Ng2, and the Mth intra-group arbitration unit 18 (M) bus use request signal req1gM to
NgM is supplied respectively. Also in this case, one bus use request signal, for example, req1, is supplied to only one intra-group arbitration unit, for example, the first intra-group arbitration unit 18 (1), and is supplied to two or three intra-group arbitration units, respectively. Not supplied.

The first intra-group arbitration unit 18 (1) performs arbitration processing based on the bus use request signals req1s1 to Ns1 supplied from the bus use request signal selection unit 17, and arbitrates the bus use permission signals req1g1 to Ng1. Is supplied to the inter-group arbitration unit 19. Second intra-group mediation section 1
8 (2) performs arbitration processing based on the bus use request signals req1s2 to Ns2 supplied from the bus use request signal selection unit 17, and the arbitrated bus use permission signals req1g2 to req1g2.
Ng2 is supplied to the inter-group arbitration unit 19. The M-th intra-group arbitration unit 18 (M) includes the bus use request signal selection unit 1
Bus use request signals req1sM to Ns supplied from
Arbitration processing based on M is performed, and the arbitrated bus use permission signals req1gM to NgM are supplied to the inter-group arbitration unit 19.

The inter-group arbitration unit 19 uses the bus use permission signal r supplied from the first intra-group arbitration unit 18 (1).
eq1g1 to Ng1, second intra-group arbitration unit 18
Bus use permission signal req1s2 supplied from (2)
Ns2, the bus use permission signals req1sM to NsM supplied from the M-th intra-group arbitration unit 18 (M) from the inter-group arbitration setting signal and bus use permission signal generation unit 20 supplied from the inter-group arbitration setting unit 28. Inter-group arbitration is performed based on the supplied bus use permission signals ack1 to N, and the arbitrated bus use request signals req1a to Na.
Is supplied to the bus use permission signal generator 20. The bus use permission signal generation unit 20 outputs the bus use permission signals ack1 to N to the module that permits the bus access this time based on the bus use request signals req1a to Na supplied from the inter-group arbitration unit 19.

Here, FIG. 10 is an explanatory diagram showing an example of the inter-group arbitration method for each setting item stored in the internal memory of the inter-group arbitration setting unit 28 shown in FIG.

As shown in FIG. 10, in the example of the inter-group arbitration method, when the inter-group arbitration setting item is 1, the inter-group arbitration method is fixed priority arbitration, and when the inter-group arbitration setting item is 2. Indicates that the inter-group arbitration method is round robin arbitration, and the inter-group arbitration setting unit 28 outputs an inter-group arbitration setting signal indicating the inter-group arbitration method. Since the inter-group arbitration method can be selectively set as described above, the bus arbitration optimal for any application can be realized.

Next, FIG. 11 is an explanatory diagram showing the stored contents of the fixed priority arbitration table used in the fixed priority arbitration executed by the first intra-group arbitration unit 18 (1) shown in FIG. is there.

As shown in FIG. 11, the fixed priority table used in the first intra-group arbitration unit 18 (1) is
The current input state of the bus use request signal and the output state of the bus use request signal after the fixed priority arbitration are stored. However, here, in the group setting unit 16,
Bus use request signal req1, bus use request signal req
2, bus use request signal req3, bus use request signal re
Each of q4 is set to the arbitration group 1.

From the bus use request signal selector 17, bus use request signals req1s1, req2s1, req3s1,
When req4s1 is output and supplied to the first intra-group arbitration unit 18 (1), the bus use request signal req is output according to the contents of the fixed priority table shown in FIG.
It is determined that 1s1 is the bus use request signal having the highest priority in the arbitration group 1, and req1g1 is output as the bus use request signal after arbitration. Further, only the bus use request signal req4s1 is output from the bus use request signal selection unit 17, and the signal is output to the first intra-group arbitration unit 18
When supplied to (1), it is determined that the bus use request signal req4s1 is the highest priority bus use request signal in the arbitration group 1 according to the contents of the fixed priority table,
Req4g1 is output as a bus use request signal after arbitration. Further, even when the bus use request signal selecting unit 17 outputs the bus use request signals in other combinations, the fixed priority arbitration is performed according to the contents of the fixed priority table shown in FIG. 11, and the highest priority is obtained at that time. A high bus use request signal is output. The second intra-group arbitration unit 18 (2) and the M-th intra-group arbitration unit 18
Also in (M), the first intra-group arbitration unit 18 (1)
The same operation as that performed in step 1 is performed, and the bus use request signal having the highest priority at that time is output.

Next, FIG. 12 is a block diagram showing an example of the configuration of the inter-group arbitration unit 19 shown in FIG. However, here, in order to simplify the description, it is assumed that round robin arbitration is selected as the inter-group arbitration method.

As shown in FIG. 12, the inter-group arbitration setting unit 19 includes a round robin table 29, a previous access storage unit 30, and a bus use request signal input terminal 31.
And a bus use request signal input terminal 32 and a bus use request signal output terminal 33.

Then, the previous access storage section 30 includes the round robin table 29 and the bus use permission signal input terminal 3
Connected to 2. The round robin table 29 is connected to the bus use request signal input terminal 31 and the bus use request signal output terminal 33.

In this case, the previous access storage unit 30 stores the module that accessed the bus last time and outputs the previous access signal.
9 is for performing round robin arbitration.

In this case, FIG. 13 is an explanatory diagram showing an example of the stored contents of the round robin table 29 shown in FIG. 12, and shows an example in which the number of modules N is four.

The operation of the inter-group arbitration setting unit 19 shown in FIG. 12 will be described based on the stored contents of the round robin table 29 shown in FIG.

In the inter-group arbitration setting unit 19, the previous access signal output from the previous access storage unit 30 is the module 4 (req4s1), and the current bus use request is input to the bus 1 using the module 1 (req4s1). req1g1), module 2 (req2g
1), module 3 (req3g1), module 4
If it is output from (req4g1), the module 1 (re
It is determined that q1s1) is the bus use request signal having the highest priority, and the bus use request signal req1a is output through the bus use request signal output terminal 33. At this time, when the bus use permission signal generation unit 20 generates the bus use permission signal ack1 for the module 1, the module 1 is stored in the previous access storage unit 30.

Next, as the current bus use request, module 1 (req1s1) and module 2 (req2s)
1), module 3 (req3s1), module 4
If it is output from (req4s1), module 2 (req2s1) according to the round robin table 29.
Is the bus use request signal with the highest priority,
The bus use request signal req2a is output through the bus use request signal output terminal 33. At this time, when the bus use permission signal generation unit 20 generates the bus use permission signal ack2 for the module 2, the module 2 is stored in the previous access storage unit 23.

Next, as the current bus use request, module 1 (req1s1), module 2 (req2s)
1), module 3 (req3s1), module 4
If it is output from (req4s1), module 3 (req3s1) according to the round robin table 29.
Is the bus use request signal with the highest priority,
The bus use request signal req3a is output through the bus use request signal output terminal 33. At this time, when the bus use permission signal generation unit 20 generates the bus use permission signal ack3 for the module 3, the module 3 is stored in the previous access storage unit 30.

Similarly, as the current bus use request, module 1 (req1s1), module 2 (req2s)
1), module 3 (req3s1), module 4
If it is output from (req4s1), module 4 (req4s1) according to the round robin table 29.
Is the bus use request signal with the highest priority,
The bus use request signal req4a is output through the bus use request signal output terminal 33. At this time, when the bus use permission signal generation unit 20 generates the bus use permission signal ack4 for the module 4, the module 4 is stored in the previous access storage unit 30.

As described above, according to the inter-group arbitration setting unit 19, even when some bus use requests are made at the same time, the bus arbitration can be equally performed on the modules 1 to 4. Also, when the inter-group arbitration setting unit 19 is set to perform fixed priority arbitration, similar bus arbitration is performed with only a slightly different setting method.

Next, FIG. 14 shows an operation procedure viewed from the software side in the bus arbitration device 6 shown in FIG. 2 or FIG. 9, and is a flowchart at the time of task access executed on the software. is there.

Now, the flow chart shown in FIG. 14 will be described. However, in the bus arbitration device 6 illustrated in FIG. 9, it is assumed that the inter-group arbitration setting unit 28 is set to perform fixed priority arbitration with respect to the inter-group arbitration unit 19.

First, in order for task A (S10) to read a file, the operating system (kernel)
A system call (S11) is executed for (S12).

Next, the operating system (kernel) receives this system call (S11) and executes the input / output access A (S13).

When the input / output access A (S13) is executed, the input / output control (S14) first sets the task priority to the bus priority. That is, the task priority is inherited by the bus priority.

Here, FIG. 15 shows an example of a quantization table used when the task priority levels 0 to P (lower values have higher priority levels) are changed to bus priority levels. It is an explanatory view shown.

As shown in FIG. 15, the quantization table quantizes the priorities of tasks from 0 to P into bus access priorities from 1 to M (where M is the number of groups). It is a thing.

After that, the actual input / output control (S14) is started. Here, the operation system (kernel) (S12) performs task switching (S20) in order to execute the next task until the processing of task A (S10) is completed.

When the task switching (S20) is performed, the next task, task B (S21), is executed. In task B (S21), a file read system call (S22) is executed as in task A (S10).

Operating system (kernel) (S
In response to this, 12), when the input / output access B (S23) for executing the input / output access B (S23) is executed,
The input / output control (S14) first sets the task priority to the bus priority even during the task A (S10) input / output control processing.

When the input / output processing in the input / output control (S14) is completed (S17), the operation system (kernel) (S12) is notified of the completion, so an interrupt request (S19) due to the completion of the input / output processing is issued. Occur.

After that, when there are no remaining input / output accesses that have been waited for, the state before the bus access priority is set is returned (S18).

Next, FIG. 16 is a flowchart showing the operation history when setting the priority of bus access in the input / output control (S14) in the flowchart shown in FIG.

The operation for setting the priority of bus access will be described with reference to the flow chart shown in FIG.

First, in step S30,
Determine if an I / O access is occurring. Then, it is determined that the input / output access is occurring (YE
In the case of S), the process proceeds to the next step S31. On the other hand, when it is determined that the I / O access has not occurred (NO), this series of processes is ended.

Next, in step S31, since an input / output access has occurred, the priority of the task is set as shown in FIG.
Quantization is performed according to the quantization table shown in FIG.

Then, in step S32, the quantized task priority is set as the bus access priority.

Succeedingly, in a step S33, the input / output access is executed according to the set priority of the bus access.

In the following step S34, it is determined whether or not an input / output access by another task has occurred. Then, when it is determined that the input / output access by another task is occurring (YES), the process proceeds to the next step S35, while it is determined that the input / output access by another task is not occurring (NO). ), The process proceeds to other step S36.

Next, in step S35, since an input / output access has occurred, the priority of the task is set as shown in FIG.
Quantization is performed according to the quantization table shown in FIG.

Then, in step S37, it is determined whether the quantized bus access priority is higher than the currently set bus access priority. And
When it is determined that the priority is higher than the currently set bus access priority (YES), the process proceeds to the next step S38,
On the other hand, if it is determined that the priority of the currently set bus is lower (NO), the process proceeds to another step S36.

Then, in step S38, the priority of the quantized task is set as the priority of the bus access because it is higher than the currently set priority of the bus access.

In the following step S36, it is determined whether or not the input / output access is completed. Then, if it is determined that the input / output access is already completed (YES), the process proceeds to step S39, while if it is determined that the input / output access is not yet completed (NO), the previous step S39 is performed.
Returning to step S34, the processing from step S34 is repeatedly executed.

Next, in step S39, since the input / output access is completed, an end interrupt request for the completed access is generated.

Then, in step S40, it is determined whether or not there is a waiting input / output access. Then, if it is determined that there is a waiting input / output access (YES), the process returns to the previous step S33, and the processing after the step S33 is repeatedly executed, while it is determined that there is no waiting input / output access. In the case of (NO), the process proceeds to the next step S41.

Then, in step S41, the bus access priority is returned to the state before switching to the task priority. When this processing is performed, this series of processing ends.

Through such a background, the task priority can be reflected in the bus access priority.

In the bus arbitration device 6 in each of the above embodiments, a non-volatile memory can be used for the table used in the group setting unit 16 and the inter-group arbitration setting unit 28.

[0121]

As described above, according to the invention described in claim 1, the bus arbitration device includes the group setting means, the intra-group arbitration means, the inter-group arbitration means, and the bus use permission signal generating section, and the group The setting means assigns and sets multiple modules to any of the arbitration groups, performs arbitration processing based on the bus usage request for each arbitration group set by the intra-group arbitration means, and then performs inter-group arbitration means between the arbitration groups. Arbitration processing is performed to select the module that permits bus access, and the bus usage permission signal generator supplies the bus usage permission signal to the selected module. The effect is that the optimum bus arbitration priority can be set for any application.

According to the second aspect of the present invention, the bus arbitration device includes group setting means, intra-group arbitration means, inter-group arbitration setting means, inter-group arbitration means, and a bus use permission signal generating section. The group setting means assigns and sets a plurality of modules to any of a plurality of arbitration groups, performs arbitration processing based on the bus use request for each arbitration group set by the intra-group arbitration means, and multiple arbitration settings by the inter-group arbitration setting means. Set the arbitration method between groups, and then perform the arbitration processing between the arbitration groups by the arbitration means between groups according to the set arbitration method, select the module that permits bus access, and select by the bus use permission signal generator. Since the bus permission signal is supplied to the module,
It is possible to set the optimum bus arbitration priority for an arbitrary application and to perform the bus arbitration by the optimum arbitration method without creating a large number of priority tables.

Further, according to the invention of claim 7,
Since the priority of tasks when multiple modules perform data processing is set according to the priority of bus access to the shared bus, priority should be given to bus access to high-priority tasks. Therefore, there is an effect that a task having a high priority can be quickly executed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a main configuration of a data processing system according to the present invention.

2 shows a first embodiment of a bus arbitration device used in the data processing system shown in FIG. 1, and is a block diagram showing a main configuration thereof.

FIG. 3 is an explanatory diagram showing an example of group setting values stored in a group setting register built in the group setting unit shown in FIG.

FIG. 4 is a block diagram showing an example of a configuration of a first intra-group arbitration unit shown in FIG.

5 is an explanatory diagram showing an example of stored contents of a round robin table shown in FIG. 4. FIG.

FIG. 6 is an explanatory diagram showing an example of stored contents stored in a built-in table of the inter-group arbitration unit shown in FIG.

FIG. 7 is a flowchart showing an operation history of the bus arbitration device shown in FIG.

FIG. 8 is a time chart showing an example of adjustment timing at the time of bus arbitration processing performed by the bus arbitration device shown in FIG.

9 is a block diagram showing a second embodiment of a bus arbitration device used in the data processing system shown in FIG. 1, and is a block diagram showing a main part configuration thereof. FIG.

10 is an explanatory diagram showing an example of an inter-group arbitration method for each setting item stored in a built-in memory of the inter-group arbitration setting unit shown in FIG.

FIG. 11 is an explanatory diagram showing stored contents of a fixed priority arbitration table used during fixed priority arbitration executed by the first intra-group arbitration unit shown in FIG. 9;

12 is a block diagram showing an example of a configuration of an inter-group arbitration unit shown in FIG.

FIG. 13 is an explanatory diagram showing an example of stored contents of the round robin table shown in FIG.

14 shows an operation procedure from the software side in the bus arbitration device shown in FIG. 2 or FIG.
It is a flowchart at the time of the task access performed on software.

FIG. 15 is an explanatory diagram showing an example of a quantization table used when changing the priority of a task to the priority of a bus.

16 is a flowchart showing an operation history in setting the priority of bus access in input / output control in the flowchart shown in FIG.

FIG. 17 is a block diagram showing a main configuration of a known DMA control device.

[Explanation of symbols]

1 Data processing device 2 Control unit (CPU) 3 Memory (memory) 4 Display 5 hard disk (HD) 6 Bus arbitration device 7 Control unit interface unit (CPU I / F unit) 8 Memory controller section 9 Drawing processing unit 10 Display control unit 11 Hard disk controller (HD controller) 12 Video input control section 13 Voice input controller 14 Communication control unit 15 shared buses 16 Group setting department 17 Bus use request signal selector 18 (1) First Group Mediation Department (Group 1) 18 (2) Second group mediation section (Group 2) 18 (M) Mediation Department of Mth Group (Group M) 19 Group arbitration department 20 Bus use permission signal generator 21, 25, 31 Bus use request signal input terminal 22 Bus enable signal output terminal 23, 30 last access storage 24, 29 round robin table 26, 32 Bus enable signal input terminal 27, 33 Bus use request signal output terminals 28 Group arbitration setting section

Continued front page    (72) Inventor Masahiko Saito             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Seiichi Saito             5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Ceremony Company within Hitachi Semiconductor Group (72) Inventor Yutaka Okada             5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Ceremony Company within Hitachi Semiconductor Group F-term (reference) 5B045 BB12 BB28 EE07 EE12                 5B061 BA01 BB04 BB16 BB43 BC01                       BC03 RR03                 5B098 AA07 AA10 GA04 GD01 GD15

Claims (10)

[Claims] 1. A data processing system comprising a bus arbitration device, wherein a plurality of modules and a control unit are connected to a shared bus and arbitrates bus access to the shared bus in the plurality of modules. A group setting means for assigning and setting the plurality of modules to any of a plurality of arbitration groups; an intra-group arbitration means for arbitrating bus access to the shared bus for each of the plurality of arbitration groups; An inter-group arbitration unit that arbitrates bus access to the shared bus between groups; and a bus use permission signal generation unit that supplies a bus use permission signal to the module arbitrated by the inter-group arbitration unit. Data processing system. 2. A data processing system, comprising: a plurality of modules and a control unit connected to a shared bus; and a bus arbitration device for arbitrating bus access to the shared bus in the plurality of modules, wherein the bus arbitration The device includes a group setting unit that assigns and sets the plurality of modules to any of a plurality of arbitration groups, an intra-group arbitration unit that arbitrates bus access to the shared bus for each of the plurality of arbitration groups, and the plurality of units. Inter-group arbitration setting means for setting an arbitration method between arbitration groups, and inter-group arbitration for arbitrating bus access to the shared bus between the plurality of arbitration groups by the arbitration method set by the inter-group arbitration setting means Means and the module arbitrated by the inter-group arbitration means to provide a bus use permission signal. A data processing system comprising: a bus use permission signal generating unit for supplying the data. 3. The group setting means has a non-volatile memory, and the plurality of arbitration groups corresponding to a plurality of modules are stored in the non-volatile memory. Data processing system. 4. The inter-group arbitration setting means has a non-volatile memory, and different arbitration methods corresponding to inter-group arbitration setting items are stored in the non-volatile memory. Data processing system. 5. The data processing system according to claim 4, wherein the different arbitration methods are a fixed priority arbitration method and a round robin arbitration method. 6. The group setting means is capable of writing and reading a plurality of arbitration groups corresponding to a plurality of modules in the nonvolatile memory under the control of the control unit. Data processing system. 7. The inter-group arbitration setting means is capable of writing and reading different arbitration methods corresponding to inter-group arbitration setting items in the non-volatile memory under the control of the control unit. The data processing system according to 4 or 5. 8. The priority of a task when the plurality of modules perform data processing is set corresponding to the priority of bus access to the shared bus. Data processing system. 9. The priority of a task when the plurality of modules perform data processing is changed according to the priority of a bus access to the shared bus. Data processing system. 10. The priority of a task when the plurality of modules perform data processing is set, when a task having a priority lower than the priority of the currently set task is executed. The data processing system according to claim 9, wherein no change is made.