JPH0668025A - Bus access control system - Google Patents

Abstract

PURPOSE:To improve the efficiency of information transfer passing an external bus as much as possible with respect to the bus access control system for the information processing system where plural communication equipments internally transfer information through an internal bus and mutually transfer information through the external bus. CONSTITUTION:Each communication equipment 100 is provided with an external bus request means 102 and an external bus cancelling means 103, and the external bus request means 102 sends a bus use request signal, which requests the use of the external bus, to the external bus if any information transfer request of mutual transfer of information passing the external bus 200 is generated in the communication equipment, and the external bus cancelling means 103 sends a bus use cancel signal, which cancels the external bus use request sent by the external bus request means, to the external bus when it is confirmed that the information transfer request does not use the external bus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transfers information internally via internal buses incorporated in a plurality of communication devices and mutually transfers information via an external bus connecting each communication device. Bus access control method in an information processing system for

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing an example of a conventional information processing system, and FIG. 5 is a diagram showing an example of an information transfer process in FIG.

The information processing system shown in FIG. 4 has two sets.
Communication device 1 (individual communication device 1 ₁And 1₂Call
The same applies hereinafter) and the synchronous bus 2.
Communication device 1₁Is a processor 11, an internal register 12 and
And the bus connection control unit 13 and the internal bus that connects the above-mentioned devices.
And a communication device 1₂The bus connection
Continuation control unit 13 and external register 15 and the above two devices
And an internal bus 14 for connection.

Each communication device 1 is connected to the synchronous bus 2 via a bus connection control unit 13. Synchronous bus 2
Is provided with a bus handler 21 that permits each communication device 1 to use the synchronous bus 2.

The internal bus 14 in each communication device 1 adopts asynchronous data transfer, while the synchronous bus 2 adopts synchronous data transfer. 4 and 5, at time t _21, the external register 15 ₂ of the communication device 1 in ₂ from the processing unit 11 ₁ of the communication device 1 _1, the request processing device for transferring and storing the required data (DT) When it occurs at 11 ₁ , the processor 11 ₁ sends a bus cycle start signal (BS) indicating that the use of the internal bus 14 ₁ is started to the internal bus 14 ₁ , and then at time t ₂₂ , the external register 1
5 and data including the _second identification information (DT), data (D
The data confirmation signal (DS) indicating the transmission of T) is sent to the internal bus 14 ₁ .

The bus connection control unit 13 ₁ has an internal bus 14 ₁
After receiving the bus cycle start signal (BS) arriving from, and subsequently receiving the data (DT) based on the data confirmation signal (DS) arriving subsequently, at time t ₂₃ , the data reception notification signal (DC) is transmitted. When sent, the processor 11 ₁ receives the data receipt notification signal (DC) from the internal bus 14 _1.
Is received, the transmission of the data (DT) being transmitted to the internal bus 14 ₁ and the data confirmation signal (DS) is stopped at time t ₂₄ .

Bus connection control unit 13₁Is the received data
(DT) is inspected for the presence of an error, and then the data (D
The transfer destination of T) is the communication device 1₁Internal equipment (eg internal cash register)
Star 12₁) Or communication device 1₁Outside equipment
(For example, the communication device 1₂External register 15 in₂) Is
I analyzed it, this time communication device 1₁External external register 15
₂When it is identified that the request signal sending unit 131 is built-in
₁To start.

The activated request signal transmitter 131 ₁ follows the synchronous procedure adopted in the synchronous bus 2 at time t.
_{From 25 to} t ₂₆ , a bus use request signal (RQL) requesting use of the synchronous bus 2 is transferred to the bus handler 21 via a dedicated signal line.

[0009] bus handler 21, at the stage of receiving the bus request signal transferred from the communication device 1 ₁ (RQL), allows the use of synchronous bus 2 to the communication device 1 ₁ If possible, to the time t ₂₆ At t ₂₇ , a bus use permission signal (GRM) permitting use of the synchronous bus 2 is returned to the communication device 1 ₁ via a dedicated signal line.

In the communication device 1 ₁ , when the bus connection control unit 13 ₁ receives the bus use permission signal (GRM) returned from the bus handler 21, it is determined that the use of the synchronous bus 2 is permitted, and the time t is reached. _{From 28 to} t ₂₉ , the processing device 11
Data Received from ₁ via the internal bus 14 ₁ (D
T) is transferred to the communication device 1 ₂ via the synchronous bus 2.

In the communication device 1 ₂ , when the bus connection controller 13 ₂ receives the data (DT) arriving from the synchronous bus 2, the transfer destination of the data (DT) is a device within the communication device 1 ₂ (for example, an external register). 15 analyzes whether _2), when identified as a external register 15 ₂ of the communication device 1 in _2, in accordance with known procedures, then transferred to an external register 15 ₂ via the internal bus 14 _2, storage To do.

[0012]

[Problems to be Solved by the Invention]
Thus, in the conventional information processing system,
Storage 11₁Is the external register 15₂Data to be transferred to (D
T) internal bus 14₁Connection control when sending to
Part 13₁Is the internal bus 14₁Data received via
As a result of analyzing the presence or absence of (DT) error and the transfer destination,
After determining that it is necessary to transfer via the synchronous bus 2.
The bus use request signal (RQ
L) is transferred, and as a result, the bus is used from the bus handler 21.
Data (DT) only after the permission signal (GRM) is returned.
Transfer has started, processing device 11 ₁Is the data (D
After the transmission of T) is completed, the data (DT) is
15₂(T) in FIG.
Time t_{twenty four}From time t₂₉Up to a long time, data (D
There is a problem that the transfer efficiency of T) decreases.

An object of the present invention is to improve the information transfer efficiency via an external bus as much as possible.

[0014]

FIG. 1 is a diagram showing the principle of the present invention. In FIG. 1, 100 is a plurality of communication devices,
Reference numeral 101 is an internal bus that is built in each communication device 100 and internally transfers information, and 200 is an external bus that connects the communication devices and transfers information between the communication devices 100.

Reference numeral 102 denotes each communication device 100 according to the present invention.
It is an external bus requesting means provided in the. 103 is an external bus canceling unit provided in each communication device 100 according to the present invention.

[0016]

The external bus requesting means 102, when an information transfer request for either internal transfer of information via the internal bus 101 or mutual transfer of information via the external bus 200 occurs in the communication device 100, A bus use request signal requesting use of the external bus 200 is sent to the external bus 200.

The external bus canceling means 103, when it is determined that the information transfer request does not use the external bus 200,
A bus use cancel signal for canceling the use request of the external bus 200 sent by the external bus request means 102 is sent to the external bus 200.

Note that the external bus canceling means 103 is considered to transfer the bus use cancel signal to the external bus 200 via a path independent of information transfer between the communication devices 100 via the external bus 200, and also cancels the bus use. It may be considered to transfer arbitrary information as a signal via the external bus 200 permitted to be used, and terminate the use of the bus assuming that the information transfer to the external bus 200 is completed.

Therefore, the bus use request signal is sent to the external bus immediately when the information transfer request is generated in the communication device, and the bus use cancel signal is sent when the external bus is no longer needed. The time required until the external bus can be used is shortened by the time spent for confirming that the external bus is used, and the information transfer efficiency of the information processing system is improved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 2 is a diagram showing an information processing system according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of an information transfer process in FIG. The same reference numerals denote the same objects throughout the drawings.

In FIG. 2, the communication device 1 in FIG.
00, two sets of communication devices 1 are provided, a synchronous bus 2 is provided as an external bus 200 in FIG. 1, and an internal bus 14 is provided as an internal bus 101 in FIG. 1 in each communication device 1. Further, a request signal sending unit 16 and a cancellation control unit 132 are provided as the external bus requesting unit 102 and the external bus canceling unit 103 in FIG. 1, respectively. Instead, each bus connection control unit 13 in the communication device 1 is provided. The request signal sending unit 131 is removed from FIG.

[0022] In Figures 2 and 3, at time t _1, the external register 15 ₂ of the communication device 1 in ₂ from the processing unit 11 ₁ of the communication device 1 _1, a request for transferring and accumulating the required data (DT) Occurs in the processing device 11 ₁ , the processing device 1 1
1 _1, by a process similar to that described above, after sending the bus cycle start signal (BS) to the internal bus 14 _1, time t
₂ , the data (DT) and the data confirmation signal (DS) are sent to the internal bus 14 ₁ .

The bus connection control unit 13 ₁ receives the bus cycle start signal (BS) arriving from the internal bus 14 _{1 in} the same process as described above, and then uses the data confirmation signal (DS) arriving subsequently as a reference. After receiving the data (DT)
Dispatched time t _3, when transmitted data acknowledgment signal (DC), the processor 11 ₁ receives the data acknowledgment signal (DC) coming from the internal bus 14 _1, at time t _4, the internal bus 14 ₁ The transmission of the middle data (DT) and the data confirmation signal (DS) is stopped.

On the other hand, the request signal transmission section 16 ₁ includes the processing device 1
When the bus cycle start signal (BS), data (DT) and data confirmation signal (DS) sent from 1 ₁ to the internal bus 14 ₁ are received in parallel with the bus connection control unit 13 ₁ , the data (DT) transfer destination regardless of any communication device 1 ₁ and out, at a time t ₅ to t _6, a bus use request signal (R
QL) to the bus handler 21 via a dedicated signal line.

The bus handler 21, in the same manner as described above, at the stage of receiving the bus request signal transferred from the communication device 1 ₁ (RQL), allowed if the synchronization use of the bus 2 to the communication device 1 ₁ At time t _{6 to} t ₇ , the bus use permission signal (GRM) is returned to the communication device 1 ₁ via the dedicated signal line.

On the other hand, the bus connection control unit 13₁Received data
After checking the data (DT) for errors, the data (D
The transfer destination of T) is the communication device 1₁Internal device, or
Communication device 1₁It analyzes whether it is an external device, this time it is a communication device.
Setting 1₁External external register 15 ₂If you identify
A bus use permission signal (GRM) is returned from the handler 21.
After confirming that₈To t₉To the processing
Device 11₁To internal bus 14₁Day received via
Data (DT) via the synchronous bus 2 to the communication device 1₂Turn to
To send.

In the communication device 1 ₂ , the bus connection control unit 13 _{2 transfers} the data (DT) received from the synchronous bus 2 to the external register 15 ₂ via the internal bus 14 ₂ in the same process as described above. And accumulate.

Next, at time t _11, the internal registers of the communication device 1 ₁ from the processor 11 ₁ of the communication device 1 ₁ 12
_When a request for accumulating the required data (DT) is issued to the processor 11 ₁ at ₁ , the processor 11 ₁ sends a bus cycle start signal (BS) to the internal bus 14 ₁ by the same process as described above. After that, at time t ₁₂ , the data (DT) and the data confirmation signal (DS) are sent to the internal bus 14 ₁ .

The bus connection control unit 13 ₁ receives the bus cycle start signal (BS) arriving from the internal bus 14 _{1 in} the same process as described above, and then uses the data confirmation signal (DS) arriving subsequently as a reference. After receiving the data (DT)
Dispatched time t _13, when sending the data acknowledgment signal (DC), the processor 11 ₁ receives the data acknowledgment signal (DC) coming from the internal bus 14 _1, at time t _14, the internal bus 14 ₁ The transmission of the middle data (DT) and the data confirmation signal (DS) is stopped.

On the other hand, the request signal sending unit 16 ₁ sends the bus cycle start signal (BS), data (DT) and data confirmation signal (DS) sent from the processing unit 11 ₁ to the internal bus 14 ₁ as described above. When receiving in parallel with the bus connection control unit 13 _1, the transfer destination is the communication device data (DT) 1
_The bus use request signal (RQL) is transferred to the bus handler 21 via a dedicated signal line from time t _{15 to} time t ₁₆ regardless of whether it is internal or external.

The bus handler 21, in the same manner as described above, at the stage of receiving the bus request signal transferred from the communication device 1 ₁ (RQL), allows the use of synchronous bus 2 to the communication device 1 ₁ if At time t _{16 to} t ₁₇ , the bus use permission signal (GRM) is returned to the communication device 1 ₁ via the dedicated signal line.

On the other hand, the bus connection control unit 13₁Received data
After checking the data (DT) for errors, the data (D
The transfer destination of T) is the communication device 1₁Internal device, or
Communication device 1₁It analyzes whether it is an external device, this time it is a communication device.
Setting 1₁Internal register 12 in ₁If you identify
It is determined that it is not necessary to use the term bus 2 and the processing device 11 ₁
To internal bus 14₁Received data via DT (DT)
Is not sent to the synchronous bus 2 and the bus handler 21
Confirm that the use permission signal (GRM) has been returned
Then, the use of the synchronous bus 2 which is permitted to be used is canceled.
Cancellation control unit 132₁To start.

When the cancellation control unit 132 ₁ is activated, it is activated at time t.
_{From 18 to} t ₁₉ , the bus use cancel signal (CAN) is transferred to the bus handler 21 via a dedicated signal line. Bus handler 21 receives the bus use cancellation signal transferred from the communication device 1 ₁ (CAN), cancel the permission to use the synchronous bus 2 are applied to the current communication device 1 _1.

As is clear from the above description, the present embodiment
According to the communication device 1₁Internal processing unit 11₁Data (D
When the transfer request of (T) is generated, the request signal sending unit 16₁But
The transfer destination of the data (DT) is the communication device 1₁Inside or outside
Immediately, a bus use request signal is immediately sent to the bus handler 21.
(RQL) and transfers the bus connection control unit 13 between them.₁But
The transfer destination of the data (DT) is analyzed, and the transfer destination is the communication device 1
₁External external register 15 ₂If it is determined that the bus
Via the synchronous bus 2 which has already received the use permission signal (GRM)
Data (DT) is transferred by the communication device 1₁Inside
Internal register 12 ₁If it is determined that the bus hand
Transfer the bus use cancellation signal (CAN) to
Processing device 11 to cancel the use of space 2₁Is the data (D
After the transmission of T) is completed, the data (DT) is
15₂The time required to complete the storage in
Time t_{twenty four}To t₂₉From time (T) of
Time t _FourTo t₉Can be significantly shortened in the time (T ')
Become.

2 and 3 are merely embodiments of the present invention, and the external bus canceling means 103, for example, like the canceling control section 132, uses the dedicated signal line to cancel the bus use canceling signal ( It is not limited to the one that transfers CAN) to the bus handler 21, and the data (DT) that means bus use cancellation is transferred to the communication device 1 ₂ via the synchronous bus 2 which has been permitted to be used. The handler 21 monitors that the data (DT) has been transferred via the synchronous bus 2,
Etc. to stop permission to use the synchronous bus 2 that has been given to the communication device 1 _1, although other numerous variations are considered, the effect does not change the present invention in any case. Further, the configuration of the communication device 100 which is a target of the present invention is not limited to the illustrated communication device 1, and various modifications are considered, but in any case, the effect of the present invention is different. Absent.

[0036]

As described above, according to the present invention, in the information processing system, the bus use request signal is immediately sent to the external bus when the information transfer request is generated in the communication device.
After that, when the external bus is no longer needed, the bus use cancellation signal is sent, so the time required to use the external bus is limited to the time spent confirming that the external bus is used. This shortens the information transfer efficiency of the information processing system.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a diagram showing an information processing system according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of an information transfer process in FIG.

FIG. 4 is a diagram showing an example of a conventional information processing system.

5 is a diagram showing an example of an information transfer process in FIG.

[Explanation of symbols]

 1, 100 Communication Device 2 Synchronous Bus 11 Processing Device 12 Internal Register 13 Bus Connection Control Unit 14, 101 Internal Bus 15 External Register 16, 131 Request Signal Sending Unit 21 Bus Handler 102 External Bus Request Means 103 External Bus Canceling Means 132 Cancellation Control Part 200 External bus

Claims (3)

[Claims] 1. A plurality of communication devices (100) transfer information internally via internal buses (101) incorporated therein, respectively, and also via an external bus (200) connecting the communication devices (100). In the information processing system for mutually transferring information, the internal bus (101) is provided to each of the communication devices (100).
Internal transfer of information via the external bus (20
0), when any information transfer request of mutual transfer of information occurs in the communication device (100), a bus use request signal requesting use of the external bus (200) is transmitted to the external bus (200). External bus request means (10
2) and, when it is determined that the information transfer request does not use the external bus (200), the external bus requesting means (10)
A bus access control method, further comprising: an external bus canceling means (103) for sending to the external bus (200) a bus usage cancel signal for canceling a request for using the external bus (200) sent by the above (2). 2. The external bus canceling means (103) includes the communication device (10) via the external bus (200).
0) The bus access control system according to claim 1, wherein a bus use cancellation signal is transferred to the external bus (200) through a path independent of mutual information transfer. 3. The external bus canceling means (103) transfers arbitrary information as the bus use canceling signal via the external bus (200) permitted to be used, whereby the external bus (200) is transferred. 2. The bus access control method according to claim 1, wherein the use of the bus is terminated on the assumption that the information transfer is completed in step 200).