JPH0535458B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a data transmission device that transmits data between systems that mainly operate asynchronously.
In particular, the present invention relates to a data transmission device that selectively branches data conditionally. [Prior Art] Conventionally, a common method for transmitting data between asynchronous systems was to use FIFO (first-in, first-out) memory as a buffer between systems (interface
(See August 1984 issue, pages 268-270). for example,
When transmitting data between the A system and the B system that operate asynchronously, as shown in FIG. 6, a FIFO memory 3 is connected between the output of the A system 1 and the input of the B system 2, A system 1
A configuration is adopted to buffer the output of. Further, when data is transmitted between a plurality of asynchronous systems, a configuration is adopted in which FIFO memories 8 to 10 are connected between each asynchronous system 4 to 7, as shown in FIG. By the way, in conventional data transmission devices, FIFO memory only has a data buffering function, so if such FIFO memory is used for data transmission between asynchronous systems, multiple asynchronous systems can only be connected in series. As a result, the overall system connected by FIFO memory consists of a simple pipeline processing mechanism using cascade connections, which has an extremely low degree of freedom. In response, the applicant has developed and filed an application for a data transmission device that can provide greater flexibility when constructing an entire system by connecting asynchronous systems (Japanese Patent Application No. 60-33035). , Tokugansho
60-33036). This uses asynchronous self-propelled shift registers to configure input data transmission paths, output data transmission paths, branch data transmission paths, and merge data transmission paths, and determines whether the data on the input data transmission path is data that should be branched. is judged by a branch judgment means, and if the data should be branched, the data is given from the input data transmission path to the branch data transmission path, and otherwise, the data on the input data transmission path is given to the output data transmission path. On the other hand, when there is an empty buffer on the input and output data transmission paths, the data on the merged data transmission path is given to the output data transmission path, so that asynchronous systems can be connected not only in series but also in parallel. This is what I did. [Problems to be Solved by the Invention] By the way, it is conceivable that the above-mentioned data transmission device can be used to construct an information processing device, but in general, the operating state of the information processing device is determined by the program. There is a state before loading (cold state), a program loading state (warm state), a processing execution state after program loading (hot state), etc. Therefore, the data transmission device described above also branches data according to these operating states. It is desirable to be able to change the conditions. However, in the above-mentioned data transmission device, the data branching conditions are treated as fixed, and there is no consideration given to changing them according to the operating state, which is not desirable in terms of processing flexibility. There was a problem. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a data transmission device that can change data branching conditions depending on the operating state. [Means for Solving the Problems] The present invention configures the input data transmission line, the output data transmission line, and the branch data transmission line using self-propelled shift registers, and also enables the input data transmission line, the output data transmission line, and the branch data transmission line to be configured using self-propelled shift registers. Branch determination means for determining whether data on the input data transmission path is branch data;
In the case of branch data, there is a branch control means to be applied to the branch data transmission path and a plurality of branch conditions, and one of the branch conditions is selected and specified according to the content of the data on the input data transmission path. A branch condition generating means is provided for supplying the branch condition determining means to the branch determining means. [Operation] In the present invention, the branch condition generating means has a plurality of branch conditions, and one of the plurality of branch conditions is selected and specified according to the content of data on the input data transmission path. The branch condition is applied to the branch judgment means, and the branch condition is changed according to the operating state. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1 to 5 show a data transmission device according to an embodiment of the present invention. FIG. 1 shows an overall configuration diagram of this embodiment. In the figure, 11, 12, 13 are input data transmission lines, output data transmission lines, and branch data transmission lines configured using asynchronous self-propelled shift registers; Reference numeral 14 denotes a branch control unit that supplies the data on the input data transmission line 11 to the output data transmission line 12 or the branch data transmission line 13; 15 receives a branch condition; A branch determination unit 16 has a plurality of branch conditions, and selects one branch condition from the plurality of branch conditions on the input data transmission path 11. This is a branch condition generation unit that selects and specifies the data according to the content of the data, and supplies this to the branch determination unit 14. In addition, Figures 2 and 3 show input data transmission path 1.
1. An example of an asynchronous self-propelled shift register used for the output data transmission line 12 and the branch data transmission line 13 is shown. In Figure 2, 19 is a parallel data latch, 20 is a 3-input NAND 21, 2-input
This is a transfer control circuit (hereinafter referred to as a C element) which is constituted by NANDs 22 and 23 and provides a rising edge trigger to the parallel data latch 19. An asynchronous self-running shift register is a register that automatically shifts input data in the output direction without using a shift clock, provided that the next register is empty, and it is a register that automatically shifts input data in the output direction without using a shift clock. It has a function. This asynchronous self-running shift register has parallel data latches 19 and C
The C element 20 is composed of P0, P3
It receives two inputs and outputs two outputs P1 and P2, and the internal state of the C element 20 is determined by the states of these four signals P0 to P3, and as shown in the table below, Takes nine states of S8. In the following description, it is assumed that logical values 0 and 1 correspond to low level and high level signal values, respectively.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to perform selective branching in a data transmission device, and the branching conditions can be changed according to the operation mode, thereby greatly improving processing flexibility. There is an effect that can be done.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a data transmission device according to an embodiment of the present invention, FIGS. 2 and 3 are both circuit configuration diagrams showing an example of an asynchronous free-running shift register used in the above device, and FIG. The figure is a diagram for explaining the function of this asynchronous self-running shift register, FIG. 5 is a specific circuit configuration diagram of the above device, and FIGS. 6 and 7 are diagrams showing a conventional data transmission device. . 11... Input data transmission line, 12... Output data transmission line, 13... Branch data transmission line, 14...
Branch control unit, 15...branch determination unit, 16...branch condition generation unit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1 A data transmission device that transmits data between systems, which is a self-running type consisting of multiple data latches and a transfer control circuit at each stage that controls the data latch at each stage according to control signals from the transfer control circuit at the adjacent stage. Determine whether the data on the input data transmission path is data that should be branched based on the input data transmission path, output data transmission path, and branch data transmission path configured using shift registers, and the branch condition input from the outside. branching determination means for applying the data on the input data transmission path to the output data transmission path; and when the branching determination means determines that the data on the input data transmission path is data to be branched, branching the data to the output data transmission path; A branching control means for applying to the data transmission path; and a branching condition having a plurality of branching conditions, selecting one branching condition from the plurality according to the content of data on the input data transmission path and applying it to the branching judgment means. A data transmission device comprising a generating means.