JPS61133437A - One chip microcomputer - Google Patents

Abstract

PURPOSE:To execute a more larger job by constituting the titled microcomputer that a loader inputting an input signal to a random access memory is stored in a read only memory and an operation control section is executed according to the instruction word of a program inputted to the said random access memory after loading. CONSTITUTION:An application program is stored in a ROM 3 and the microcomputer has a function as an exclusive unit relating to the program and a function as a general-purpose unit executing a program loaded to a RAM 5. The main program stored in the ROM 3 is executed at the same time when power is applied. A signal is inputted from an input/output port 6 and when the value is '1', the loader stored in the ROM 4 is started. Then the 'program 1' is inputted from the input/output port 6 and after the load end is discriminated, the said program is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a one-chip microcomputer that improves the usage efficiency of a storage device and provides versatility.

[Prior Art] A conventional one-chip microcomputer mainly has an arithmetic control section (central processing unit trc) that performs symbol arithmetic processing.
(also called PUJ) and read-only memory <ROM
>, a random access memory (RAM), and an input/output port for inputting and outputting signals are mounted on a single chip. Among these, the ROM stores an execution program, and the RAM is used only for storing data read and written by the program.

Therefore, in order to execute many tasks, each program corresponding to the task is stored in the ROM, and the task is selected according to the signal from the input port, and the selected task is executed overtime. I try to do it. Therefore, all of the plurality of programs must be stored on the ROM, which has the disadvantage that large programs cannot be executed due to the storage capacity of the ROM. Furthermore, conventional one-chip microcomputers function only as dedicated machines for performing specialized tasks, and do not have the versatility to perform a wide variety of tasks.

[Problems to be Solved by the Invention] The present invention has been made to improve the above-mentioned drawbacks, and makes it possible to perform larger tasks and provide versatility in a one-chip micrometer computer. The purpose is to

[Means for Solving the Problems] The present invention provides at least an arithmetic control unit that performs signal performance processing, a read-only memory that stores processing procedures of the arithmetic control unit, and a random memory that can read and write data. In a one-chip microcomputer in which an access memory and an input/output port for inputting/outputting signals to the outside are mounted on a single chip, the read-only memory has input symbols from the input/output port. A rotor to be input to the random access memory is stored, and the arithmetic control unit executes the program according to the instruction words of the program input to the random access memory after being loaded onto the random access memory. It is a chip microcomputer.

In the present invention, the execution program is also stored in the RAM via the input/output port. Therefore, in the ROM,
A-data for loading a predetermined program from the input/output port is stored.

In addition, other areas of the ROM in which the rotor is stored may store dedicated programs corresponding to specific dedicated tasks. If the dedicated program is stored, the activation of the dedicated program and the activation of the rotor may be switched depending on, for example, the state of the input symbol from the input/output port.

The program loaded onto the RAM by the rotor is
Executes immediately after loading. Also, after that program finishes running, use the rotor to run other programs.
It can also be loaded and executed on AM.

In this manner, the present invention allows larger programs to be executed by using the RAM, which was conventionally used only for storing data in one-chip microcomputers, as a program storage area.

Further, when the execution of the program is finished, other programs can be loaded, resulting in versatility.

[Function] ROM1. : The stored rotor is started, for example, by turning on the power or inputting a start signal from the input/output port. The activated rotor loads the necessary execution program onto the RAM from the input/output port. Execution is then transferred to the loaded program, and the program is executed.

[Example] The present invention will be described below based on specific examples.

FIG. 1 is a block diagram showing the configuration of a one-chip microcomputer according to a specific embodiment of the present invention.

In this embodiment, an application program is stored on the ROM, and functions as a dedicated machine regarding the program,
It has the function of a general-purpose machine that can execute programs loaded onto the RAM.

CPLJ I is connected to a common bus 2, to which are connected ROM3 and ROM4, and further connected to RAM5 and an input/output capotro.

In addition to the above configuration, necessary functional elements such as address registers and registers are also included. Also, the above ROM3 and R
Although OM4 is defined as a separate block, it may be divided into different addresses within the same block.

FIG. 2 is a flowchart showing the operation of the device. The main program stored in the ROM 3 is executed when the power is turned on. At steps 100 and 101, an input/output capo rotor signal is input, and when the value is 1, the process moves to step 102, and the rotor stored in the ROM 4 is activated.

In other cases, the process moves to step 112, and in step 114, a predetermined application program stored in the ROM 3 is executed.

When proceeding to step 104, start the rotor,
"Program 1" is input from the input/output capotro, and after determining the end of loading at step 06, at step 110,
The program is executed.

Although the input/output capotro has been described as being connected to an external storage device, it may also be connected to a communication line and input data from the communication line.

[Effects of the Invention] In the microcomputer of the present invention, a rotor for inputting a program from an input/output port is stored on the ROM. Therefore, by starting this rotor,
A program can be loaded onto the RAM from the outside and executed.

Also, like the conventional one-chip microcomputer, R
AM is used not only to store data, but also as a storage area for programs. Therefore, the usage efficiency of the storage device can be improved, and versatility can be provided by executing selectively loaded programs. Furthermore, the use of RAM makes it possible to execute large programs, and since RAM is mounted on one chip, the number of terminals can be reduced compared to general-purpose computers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a one-chip microcomputer according to a specific embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the computer.

Claims (1)

[Claims] (1) At least an arithmetic control unit that performs signal arithmetic processing, a read-only memory that stores the processing procedures of the arithmetic control unit, and a random access memory that can read and write data, and input signals to the outside. In a one-chip microcomputer in which an output input/output port is mounted on a single chip, the read-only memory stores a rotor that inputs input symbols from the input/output port to the random access memory. A one-chip microcomputer, wherein the arithmetic control section executes the program according to commands of the program input to the random access memory after being loaded onto the random access memory.