JPH0330029A - Input/output simulation device of computer - Google Patents

Abstract

PURPOSE:To separately execute the simulation with regard to a specific input/ output by providing a memory mapped I/O area, a real status area, a simulation status area, a rewritable mode area, and a rewriting control means. CONSTITUTION:When a program is started, an instruction designated by a program counter from a user program is read out of an I/O area A and decoded. Subsequently, an input/output mode setting state is referred to in a mode area C. When setting is a real mode, the contents of the part concerned in a real status area B are rewritten to the data concerned, and next, the part concerned of a simulation status B' is rewritten to the same contents as the part concerned of the real status area B. When rewriting is ended, synchronous matching is contrived between the areas B,B'. When setting is a simulation mode, only the part of the area B' is rewritten, there is no influence in the area B, and data is not outputted. An area C can be changed by a bit unit, and switching of the mode can be executed separately by an input/output unit. At the time of rewriting of the area C, as well, synchronous matching of data of the areas B,B' is contrived, therefore, the continuity of the control is held.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a computer input/output simulation device.

(Prior Art) When developing a user program in a modern computer, it is often done to simulate the user program that is currently being developed by actually running it on a computer.

In such a case, it is necessary to disconnect the output wiring in order to prevent the output device from malfunctioning due to a programming error or the like, which requires complicated work prior to simulation.

Accordingly, recent input/output simulation devices for computers have been proposed that eliminate the need for disconnecting output wiring by prohibiting output operations using software.

Conventionally, in the memory of such a computer input/output simulation device, memory is allocated to the actual input/output device,
a memory mapped I/O area where input/output data is updated with the input/output device;
A real status area is provided in which the contents upon access to the /O area are saved, and a simulation status area is unrelated to access to the memory mapped I/O area.

When the operation mode is real access mode access, the input/output device is actually accessed by reading and writing p data to the corresponding location in the real status area.

On the other hand, when the operation mode is simulation mode access, only reading and writing to the corresponding part of the simulation status area is performed, and no access to the actual input/output device is performed.

(Problem to be Solved by the Invention) However, in such conventional input/output simulation devices, data rewriting processing is performed only on the real status area in the real access mode, and in the simulation access mode, data rewriting processing is performed only on the real status area. Because the data rewrite operation was performed only on the simulation status area, there was no consistency between the real status area and the simulation status area, so the switch from real mode to simulation mode was performed. There is a problem in that the continuity of control is interrupted when the simulation mode is switched from the simulation mode to the real mode.

In addition, in conventional input/output simulation devices, switching between real mode and simulation mode must be performed for all inputs and outputs at once, and switching operations cannot be performed individually for only specific inputs and outputs. The problem was that it was difficult to use.

This invention was made in view of the above-mentioned problems,
The purpose is to maintain continuity of control when switching from real mode to simulation mode or from simulation mode to real mode, and also to be able to simulate specific inputs and outputs individually. The purpose of this invention is to provide a computer input/output simulation device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a method that is allocated to an actual input/output device and maps input/output data to and from the input/output device. a memory mapped I/O area, a real status area where the contents when accessing the memory mapped I/Of!4 area are saved, and a simulation status area where the contents when simulation access is saved. , a rewritable mode area that stores whether the mode state at the time of access is real mode or simulation mode for each input/output unit, and a mode area that refers to the mode area specified by each decoded instruction when executing the user program, If this is in real mode, it accesses the memory mated I/O area and rewrites the corresponding part of the simulation status area with the same content, while in simulation mode, only the corresponding part of the simulation real status area is rewritten. The present invention is characterized by comprising: a control means for controlling;

(Function) According to such a configuration, synchronization is always maintained between the real status area and the simulation status area, so even if mode switching is performed between the real mode and the simulation mode, the control will be maintained. The continuity of the data is not interrupted, and by simply rewriting the contents of the mode area as appropriate, it is possible to simulate specific inputs and outputs individually.

(Example) Fig. 1 is an explanatory diagram showing the contents of a memory built into an input/output simulation device according to the present invention.The hardware configuration of a computer to which this type of simulation device is applied is described in various documents. Since this is well known, illustrations and explanations will be omitted.

As shown in the figure, in the memory of this simulation device, there is a memory-mapped I/O area 8 which is allocated to an actual input/output device and where input/output data is updated with the input/output device. A real status area B stores the contents of the memory mapped I/O area A during real access, a simulation status area B stores the contents during simulation access, and whether the mode state at the time of access is real mode or not. A rewritable mode area C is provided in which the simulation mode is stored for each input/output unit.

Next, FIG. 2 is a flowchart schematically showing the configuration of the data output control means, and the operation of the apparatus of this embodiment will be systematically explained below according to this flowchart.

When the program is started, the instruction specified by the program counter is read from the user program and decoded (step 201).

As is well known, the information following an instruction in this type of computer is comprised of an instruction type code, an input/output number that specifies data, and the like.

Next, according to the instruction decoding result, the mode setting state of the corresponding input/output is referred to in the mode area C (step 2
02〉.

As a result, if the setting mode is the real mode for the corresponding input/output (step 203), the contents of the corresponding part of the real status area are rewritten to the corresponding data (step 204).

Next, the corresponding part of the simulation status area B' is rewritten to the same content as the corresponding part of the real status area B (step 205).

When this rewriting process is completed, synchronization is achieved between the real status area IIILB and the simulation status area B' regarding the input/output.

On the other hand, if the setting mode is the simulation mode (step 203), a process is performed in which only the corresponding portion of the simulation status area B' is rewritten with the corresponding data (step 206).

Since this rewriting process does not affect the real status area B, no data is output to the actual input/output device.

In this way, in the device of this embodiment, data is always synchronized between the real status area B and the simulation status area B' according to the setting contents of the mode area C. Even if mode switching is performed for a specific input/output by rewriting the , the continuity of control will not be interrupted.

Furthermore, since the mode area C can be changed bit by bit, switching between the real mode and the simulation mode can be performed individually for each input/output unit, which greatly improves usability compared to conventional devices.

[Effect of the invention 1 As is clear from the above explanation, according to the present invention, when switching from real mode to simulation mode,
Control continuity is not interrupted, and switching between real mode and simulation mode can be performed individually for each input/output unit.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the contents in the memory of the input/output force simulation device according to the present invention, and FIG. 2 is a flowchart showing the configuration of the control wJ section. A...Memory mapped I/O m area B...Real status area B'...Simulation status area C...Mode area

Claims (1)

[Claims] (1) A memory mapped I/O area that is allocated to an actual input/output device and where input/output data is mapped with the input/output device, and when accessing the memory mapped I/O area. A real status area where the contents are saved, a simulation status area where the contents at the time of simulation access are saved, and a rewritable mode area where the mode state at the time of access is stored in real mode or simulation mode for each input/output unit. , When executing a user program, refers to the mode area specified by each decoded instruction, and if this is the real mode, accesses the memory mapped I/O area, and also accesses the corresponding memory mapped I/O area in the simulation status area. An input/output simulation device for a computer, comprising: a control means for rewriting a portion to the same content, while rewriting only a corresponding portion of a simulation status area in a simulation mode.