JPH01185733A - Input/output emulation system - Google Patents

Abstract

PURPOSE:To execute plural different system programs by one hardware by executing an input/output instruction as it is when a first system program is operated, and executing the input/output instruction by a second system program in an emulation mode. CONSTITUTION:An address is allocated based on whether or not it is the object of emulation by an address decision circuit 6, and when it is the object of the emulation, an NMI signal is generated by a gate 2, and a CPU starts up an emulation program. At this time, the next input/output instruction is switched to a first system port by a flip-flop 5. The emulation program decides whether a start-up factor is input (IOR) or output (IOW), and when it is the input, sets data equivalent to the input data of a second system port on an emulation memory 7, and when it is the output, emulates the output data by the first system port. After completing a processing, an NMI permission signal to validate the start-up of the next emulation is issued. In such a way, it is possible to execute two systems by one hardware, and to reduce the number of circuits at minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an input/output emulation method used in an information processing apparatus that executes different system programs on the same hardware.

(Prior Art) Recently, two system programs can be executed on the same hardware. Information processing devices called so-called multi-personality systems have appeared. With a multi-personality system, all applications that can be executed by each system program can be executed, allowing effective use of software assets.

(Problem to be solved by the invention) By the way, in order to run two conventional system programs on the same hardware, the address (port number) of the input/output command executed by each system program must be Because they were different, the hardware circuit was designed to be compatible with either system program. Therefore, the amount of hardware circuitry has become extremely large.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an input/output emulation method that realizes a plurality of different system programs on the same hardware by adding a small amount of hardware.

[Structure of the Invention] [Means and Operations for Solving the Problems] The present invention provides an information processing apparatus in which different system programs are executed on the same hardware, and when a first system program operates, input/output commands are It is executed as is, and input/output commands by the second system program are executed by emulation. Therefore, a flip-flop in which an emulation mode is set, an emulation memory in which emulation data of an input/output instruction is stored, and an address determination circuit that determines whether or not a corresponding input/output port is an emulation target by executing an input/output instruction. A gate that generates an interrupt signal for starting emulation when an input/output instruction is executed at an input/output port to be emulated, and a gate that is activated by the interrupt signal.
An emulation program is added that issues an interrupt permission to enable the emulation to start immediately after the input/output command emulation processing is completed.

This allows multiple different system programs to be executed on one piece of hardware.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a gate that determines whether the input/output command is executed by the first system program. Reference numeral 2 denotes a gate that generates an emulation activation interrupt signal (NMI) in response to an input/output instruction executed by the second system program. Reference numeral 3 denotes a gate that determines whether or not the input command is from the second system program, and 4 represents a gate that determines whether or not the input/output command is unique to the second system program. Reference numeral 5 denotes a flip-flop that invalidates the input/output command of the first system program during emulation and validates it when emulation is activated.

6 is an address determination circuit that determines whether an input/output instruction executed by the second system program is an emulation target; 7 is an address determination circuit that determines whether the input/output command executed by the second system program is an emulation target; It is a stored memory.

FIG. 2 is a flowchart showing the processing procedure of the emulation program used in the present invention.

Hereinafter, the operation of the embodiment of the present invention will be explained in detail. First, an emulation signal becomes active when the system is started up, and thereafter, when an input/output instruction from the CPU is executed, an input/output signal 10R/IOW and an address signal are generated. The address is determined by the address determination circuit 6 as to whether it is a target for emulation or not. If the address is a target for emulation, an NMI signal is generated by the gate 2, thereby causing the CPU to start the emulation program.

When the NMI signal is generated, the flip-flop 5 switches the missing input/output instruction to the first system port. The emulation program operates as shown in the flowchart of FIG. If it is an output, this output data is emulated at the first system port, and if this affects the input to the second system port, the data to be input is set in the emulation memory 7. . After each input/output emulation process is completed, in order to enable the next emulation startup,
Issue an NMI permission signal and end emulation.

In the emulation of input commands, the above-mentioned emulation program is activated, but the input data actually taken in by the CPU is obtained from the emulation memory 7.

In other words, the emulation program at this time transfers the next input data to the emulation memory 7.
It is set in advance. Note that when the address determination circuit 6 determines that the address is not to be emulated, only the input/output signals 10R2/10W2 of the second system port are generated.

[Effects of the Invention] As explained above, according to the present invention, the following effects can be obtained.

(1) Two systems can be executed on one piece of hardware. In other words, programs for different machines can be executed.

(2) The amount of hardware circuitry can be reduced.

(3) Flexibility is achieved because the input/output commands of the second system port are executed by a program.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a processing procedure of an emulation program used in the present invention. 1.2.3.4...Gate, 5...Flip-flop, 6...Address determination circuit, 7...Emulation memory. To the applicant's representative and patent attorney, Takehiko Suzue.

Claims (1)

[Claims] In an information processing device that executes different system programs on the same hardware, input/output instructions when one system program operates are executed in emulation mode, and the flip-flop to which this program is set and the emulation data of the input/output instructions are An emulation memory to be stored, an address judgment circuit that allocates whether or not a corresponding input/output port is a target for emulation based on the execution of an input/output command, and an address judgment circuit for distributing an input/output port for emulation when an input/output command is executed for an input/output port to be emulated. and a gate that generates an interrupt signal, and is activated by the interrupt signal, and issues the interrupt permission to enable the next emulation activation after completion of emulation processing of the input/output instruction. Emulation method.