JPS6015983B2 - Priority selection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to information transfer, and particularly to a method for selecting destinations of requests from a plurality of data transfer units using a common data transfer path.

Conventionally, the priority selection method when this type of common data transfer fee is shared by multiple data transfer units has been to have a signal line for each data transfer unit to send a request to the data transfer control unit, and the data transfer control unit A method has been adopted in which the data transfer units use a common data transfer path after the data transfer units use a notification line for each data transfer unit to notify the results selected according to the priority order of the transfer units.

Therefore, in order to use the common data transfer path, there is a drawback that the common data transfer path cannot be used until a notification signal is received from the data transfer control unit after issuing a request from the data transfer control unit.

Furthermore, since a transfer control line is provided for each data transfer section, the number of control lines increases in accordance with the number of data transfer sections. It is an object of the present invention to provide that even after a certain delay time according to the order of priority has elapsed after receiving the availability notification signal sent from a data transfer control unit, the availability notification signal is not received by another high-priority notification signal. The above disadvantages are solved by sending a usage report signal and starting to use the common data transfer path if a certain data transfer unit requests it when it is not invalidated by the usage report signal from the data transfer unit. However, it is an object of the present invention to provide a new priority selection method that does not require separate control lines between the data transfer control section and each data transfer section.

The above-mentioned object of the present invention is to provide one or more common data transfer paths connecting a plurality of data transfer units and one data transfer control unit, and to provide information on the data transfer path that connects a plurality of data transfer units and one data transfer control unit; one availability notification line for notifying the plurality of data transfer units from the transfer control unit; and the plurality of data transfer units for reporting to the data transfer control unit that the common data transfer path is to be used. and one usage report line common to the common data transfer path, and when the data transfer control unit detects that the common data transfer path is usable, the data transfer control unit uses the availability notification line to control the data transfer agent. If the data transfer unit reports the use of the common data transfer path using the usage report line, the notification signal on the usability notification line is invalidated and the data transfer unit detects that the common data transfer path is usable based on the signal on the availability notification line, and after detecting that the common data transfer path is available, a delay time (priority If the availability notification signal on the availability notification line is valid and there is a data transfer request, the usage report line is This is achieved by a priority selection method characterized in that the common data transfer path is used to report the use to the data transfer control unit using the common data transfer path.

Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the invention.

In the figure, reference number 1 is the data transfer control unit, 2 is the common data transfer path, 3 is the availability notification line, 4 is the usage report line, 1
0. . . . 10n indicates a data transfer unit, respectively. When the data transfer control unit 1 detects that the common data transfer path 2 is available, it sends out an availability notification signal using the availability notification line 3.

Each data transfer unit 10. ...10n, after receiving the availability notification signal, the data transfer unit IQ.10n in FIG. ...
... After the delay time of ... tn in Figure 2 corresponding to 10n, if there is a request for data transfer, the usage report line is used to report the usage if the availability notification signal is valid. A signal is sent to the data transfer control section 1. Upon receiving the usage report signal, the data transfer control unit 1 invalidates the usability notification signal. When a usage report signal from a certain data transfer unit is accepted by the data transfer control unit 1, transfer requests are suppressed in other data transfer units with lower priority because the usability notification signal becomes invalid. Next, referring to FIG. 3, the operation when a request occurs in data transfer units i and i+ will be described.

The eel ranking is i>i10, and ti<ti+. When requests occur simultaneously in data transfer units i and i0,
When a usability notification signal is sent from the data transfer control unit 1, the data transfer unit i sends a usage report signal to the data transfer control unit 1 after a delay time i after receiving the usability notification signal. The data transfer control unit 1 receives the usage report signal and invalidates the usage enable signal. Information is exchanged between the data transfer section i and the data transfer control section 1 using the common data transfer path 2. On the other hand, the data transfer unit i0 attempts to send a usage report signal after a delay time ti+ after receiving the availability notification signal, but since the availability notification signal has already been invalidated, the next The exchange of information with the data transfer control unit 1 is waited until the usability notification signal is reached. Next, the present invention will be explained in more detail with reference to FIGS. 4 to 6.

FIG. 4 shows the parts of the data transfer control unit 1 necessary for the present invention.
A schematic configuration diagram showing an embodiment, FIG. 5 shows the data transfer unit 10,
-10n is a schematic configuration diagram showing an embodiment of the parts necessary for the present invention, and FIG. 6 is a time chart. In Figure 4,
Reference numerals 21 and 22 indicate a control unit and 23
is an inverter, 24 is an AND circuit, 25 is an OR circuit, 2
6 is a vacant display flip-flop, 27 is a delay circuit, 26
2 represents a differential circuit, and 29 represents a driver. In FIG. 5, 31 is a receiver, 32 is a differential circuit, 33 is a delay circuit, 34 is a data transfer request flip-flop, 35 is an AND circuit, 36 is an inverter, 37 is a usage report flip-flop, 28 is a control section, 39 indicate the respective drivers. The delay circuits 27 and 33 described above may use conventionally used delay lines, or may be constructed from counters or the like. Moreover, monostable multipipulators can also be used in place of the differentiating circuits 28 and 32. Now, data transfer units 10, 102, 103, 104
341 and 3 data transfer request flip-flops, respectively.
42, 343, 344, and the usage report flip-flops are 37, 372, 373, and 374, respectively, and the data transfer units 10, 102 plan to use the common data transfer path (bus) 2, and the data transfer units 103, 104 Now, assume that there is no plan to use the common data transfer path 2.

Furthermore, the priority order of the data transfer units 10, 102, 103, and 104 is 10.0 because the delay time of the delay circuit 33 is in the relationship <t2<t3<t4 as shown in FIG. >102>103>100. Furthermore, a free space display flip-flop 26, a data transfer request flip-flop 34, to 344, a usage report flip-flop 37, and so on. The initial value of ~374 is "0". In the initial state, the usage report line 4 is ``0'', so the signal is inverted by the inverter 23 and input to the AND circuit 24.
Since the idle signal "1" from the control unit 22 and the inverted output "1" of the empty display flip-flop 26 are applied to the AND circuit 24, the output of the AND circuit 24 is "1".
1” (that is, it is detected that it can be used).

As a result, the empty display flip-flop 26 is set and its output becomes "1", and the "1" output is given as an available notification signal to the available notification line 3 via the driver 29, and each data transfer unit 10, . . . 104. Here, since the output "1" of the flip-flop 26 is applied to the reset terminal R of the flip-flop 26 through the delay circuit 27, the differentiation circuit 28, and the OR circuit 25, the flip-flop 26 is set by the delay circuit 27. It is reset after the delay time has elapsed and its output is set to “0”.
”. Since this operation is repeated, the usable notification signal becomes a pulse signal whose time period is “1”, which corresponds to the delay time of the delay circuit 27, as shown in FIG. 6. Usable notification signal The reason why is formed as described above is to effectively activate the data transfer unit in response to a subsequent transfer request when there is no time data transfer request in the data transfer unit.The delay time of the delay circuit 27 is It is longer than that of the delay circuit 33 of the data transfer units 10, 10n.In the data transfer units 10, 102 that are scheduled to use the common data transfer unit 2, the data transfer request flip-flops 34, 342 control them, respectively. They are set by the unit 38 and are waiting for their outputs to become "1" and a usability notification signal to be sent.

When the receiver 31 receives the usability notification signal from the usability notification line 3, it takes the cusp differential and sets the usage report flip-flop 37 when the usability notification signal is still "1" after a predetermined delay time. In other words, in this example, the outputs of the data transfer request flipflops 34 and 342 of the data transfer units 10 and 102 become "1", and the "1" The output is input to each AND circuit 35. On the other hand, the available facility notification signal sent from the data transfer control unit 1 is inputted to each differentiating circuit 32 and AND circuit 35 through each receiver 31, and the signal differentiated by the differentiating circuit 32 is inputted to each delay circuit 33. The signal is input to the AND circuit 35 after receiving a predetermined delay. Here, as mentioned above, since t,<, the data transfer unit 10 with a higher priority is AND
The output of the circuit 35 is set to "1" to set the usage report flip-flop 37, and the output of the flip-flop 37 is set to "1".This "1" signal is used as a usage report signal to send data through the usage report line 4. At the same time, the data transfer unit 10 executes data transfer using the common transfer path 2. This usage report signal is sent to the data transfer control unit 1 through the receiver 21 and the OR circuit 25. The signal is applied to the reset terminal R of the empty display flip-flop 26. As a result, the flip-flop 26 is reset and its output is set to "0", so the availability notification signal becomes "0" and is invalidated. Other common data transfer path 2
A low-priority data transfer unit 102 that is scheduled to use
The delay circuit 33 also outputs a "1" signal after the delay time has elapsed, but at that point the usable notification signal is invalid, that is, "0", and the output of the NAD circuit 35 is Since it remains at "0", the data transfer unit 102 is activated by the availability notification signal generated after the data transfer of the data transfer unit 10 is completed, as shown in FIG. The common data transfer path 2 will be used.

As shown in FIG. 6, during data transfer, the availability notification signal is "0" and the usage report signal is "1", and when the data transfer is completed, the data transfer request flip-flop 3
The output of flip-flop 4 becomes “0” and the use report flip-flop 3
7 is reset, the usage report signal becomes "0".

Data transfer unit 1 that does not plan to use the common data transfer path
03,104 is data transfer request flip-flop 3
Since the outputs of 43 and 344 remain at "0", it is clear that they will not be activated. By providing a variable delay circuit 33 in the data transfer section, the priority order can be easily changed.

As explained above, the present invention provides for a request when the availability notification signal is valid after a certain delay time according to the priority has elapsed after receiving the availability notification signal from the data transfer control unit. By configuring to use a common data transfer path by sending out a usage report signal if there is a This has the effect of reducing the number of control lines to two.

Although the present invention has been described above with respect to one preferred embodiment thereof, this is merely an illustrative example, and it goes without saying that the present invention is not limited only to the embodiment described herein.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a time chart showing the sending timing of the usage report signal in response to the availability notification signal of the n data transfer units shown in FIG. 1, and FIG. Fig. 3 is a time chart when data transfer units i and i+ use a common data transfer path, Fig. 4 is a schematic configuration diagram showing an embodiment of the data transfer control unit, and Fig. 5 is an example of the data transfer unit. A schematic configuration diagram showing the embodiment, and FIG. 6 is a time chart of the operation. 1... Data transfer control unit, 2... Common data transfer path, 3... Availability notification line, 4... Usage report line, 10,, 10n... Data Transfer department, 21,
31... Receiver, 22, 38... Control section, 2
3, 36... Inverter, 24, 35... AND circuit,
25...OR circuit, 26...vacant display flip-flop, 27,33...delay circuit,
28, 32... Differential circuit, 29, 39... Driver, 3
4...Data transfer request flip-flop, 37...
...Usage report flip-flop. Mackerel, 2 figures, 3 figures, 4 crabs, chrysanthemums, 5 figures, leopards, 6 boxes

Claims (1)

[Claims] 1. One or more common data transfer paths connecting a plurality of data transfer units and one data transfer control unit, and a notification from the data transfer control unit to the plurality of common data transfer paths that the common data transfer path is available for use. one usability notification line for notifying the data transfer unit of the data transfer unit, and one line common to the plurality of data transfer units for reporting to the data transfer control unit that the common data transfer path is to be used. and a usage report line, and when the data transfer control unit detects that the common data transfer unit is usable, the data transfer control unit uses the availability notification line to notify the data transfer unit group of the common data transfer path. If the data transfer unit reports usage using the usage report line, the data transfer unit invalidates the notification signal on the availability notification line, and the data transfer unit transmits the signal on the availability notification line. detects that the common data transfer path is usable, and after detecting that the common data transfer path is available, the delay time is set according to the priority (the higher the priority, the longer the delay time is). If a data transfer request is made when the availability notification signal on the availability notification line is valid after the delay time (which is set to be short) has elapsed, the data transfer control is performed using the usage report line. The priority selection method is characterized in that the common data transfer path is used while reporting the usage to the department.