JPH03185519A - Information processor - Google Patents

Abstract

PURPOSE:To change or add specifications to a masked program by preparing a program for adding data to a fixed program or changing a certain part of the fixed program in an external memory. CONSTITUTION:When the program for adding data to the fixed program or changing a certain part of the fixed program is prepared in the external memory, the program is read out and inputted to an internal memory at the time of starting the system and stored in a subroutine. Instead of the fixed program, the subroutine in the internal memory is executed by periodically generated interruptions, in which the additional or changing processing can be applied to the processing of the fixed program. Thus, the specifications of the masked program can be changed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information processing device, particularly a one-chip microphone computer (hereinafter referred to as a microcomputer), and relates to a program control technique thereof.

[Conventional technology]

1-chip microcomputer - Basically used in single-chip mode Programs can be changed by adding external memory and using in expansion mode, or by replacing internal memory. In this case, a new mask ROM must be prepared.

However, among various types of specification changes, there are cases in which the specifications can be changed simply by adding predetermined processing to the program before the specification change. In this case, adding or changing the mask ROM is inefficient.

Note that there is also a conventional piggy microcomputer, which has a connector socket on the top of the microcomputer, and uses this socket to place all of the ROM outside the microcomputer. RO to be installed here
M is not masked and is an EPROM or EAROM.

According to this, the degree of freedom in adding and changing programs increases.

However, this piggy microcontroller is expensive, and although it is good for small-scale production, it is not suitable for mass-production for consumer use. Also, since the ROM for program execution is external,
There is a lot of electrical noise generated from the microcontroller, which has a large impact on other circuits and devices outside.

[Problem to be solved by the invention]

As mentioned above, once a conventional microcontroller is masked, no additions or changes can be made to the program written in the mask ROM, and when it is necessary to add or change this program, the mask must be used. The problem is that it has to happen again. Therefore, time is required to raise the mask, and together with the need for new mask formation, there is a problem of high costs.

The present invention has been made in view of the problems of the prior art described above, and an object thereof is to provide an information processing device that can make specification changes to a masked program. .

[Means to solve the problem]

The information processing device of the present invention includes a masked internal memory that stores a fixed program, a readable/writable internal memory, and means for confirming the presence or absence of program data in the external memory in response to an activation signal. , means for reading the program data from the external memory into the internal memory to form a subroutine when the program data exists in the external memory, means for periodically generating an interrupt signal, and responding to the interrupt signal. and means for stopping execution of the fixed program and executing the subroutine in the internal memory.

[For production]

According to the present invention, if a program for adding to the above-mentioned fixed program or changing a certain part of the fixed program is prepared in external memory, it is read into internal memory at startup and is executed as a subroutine. Stored. In response to periodically generated interrupts, a subroutine in the internal memory is executed instead of the fixed program, and additional processing or changes can be made to the processing of the fixed program.

This means that it is possible to make specification changes to the masked program.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a flowchart showing a process of reading a microcomputer specification change program into an internal RAM according to an embodiment of the information processing apparatus of the present invention. FIG. 2 is a flowchart showing interrupt processing for executing the read program.

The microcontroller of this embodiment has a first memory in its built-in mask ROM.
It has a program as shown in FIG. 2 and FIG. 2, and also has a program data storage area in a built-in RAM. In this program data storage area, program data stored in an external memory is read and stored as a subroutine, which is periodically executed. That is, at startup, the program data reading process shown in Figure 1 is executed to read the program data from the external memory, and then the interrupt process shown in Figure 2 is performed periodically (every 5 seconds) to execute the subroutine in the RAM. Execute.

Therefore, the program in this RAM becomes part of the program in the ROM. This will be explained in detail below.

In FIG. 1, when the power is turned on, the operating system enters the program data reading process and determines the presence or absence of external memory in step Sll.

If this determination is NO, in step S14,
A return subroutine command is set at the top address of the RAM that is called as a subroutine in the interrupt processing shown in FIG. 2 above.

Therefore, when the operating system reads this command, it returns to the main subroutine.

If the determination in step S11 is YES, in step 813 the number of program data in the external memory is read. Next, in step S14, it is determined whether the number of program data is "0".

If the determination in step S14 is NO, the program data is empty although the external memory exists, so step S12 is executed.

On the other hand, if the determination in step S14 is YES, a predetermined number of bytes of program data is read from the external memory in step S15, and then in step S16, the number of program data read in step S15 is read from the number of program data read in step 313. It is determined whether or not the remaining amount after subtracting the number of data obtained is "0". If the result of this judgment is NO, the process returns to step S15, and if it is YES, the program reading process is ended.

That is, if the determination in step S14 is NO and the program data exists in the external memory, step S15.
By repeating S16, only the number of bytes of program data is read, and the reading process ends.

As a result, a subroutine is formed on the RAM using the program data read from the external memory.

Next, as already mentioned, the microcontroller of this embodiment is 1m5e
The device is provided with a timer means for generating an interrupt signal every c, and the following processing shown in FIG. 2 is performed every time this interrupt signal is generated.

In FIG. 2, when an interrupt signal is generated, the operating system enters timer interrupt processing, first in step S21 saves the data in the accumulator, and in step S22, the R
Call and execute a subroutine on AM. When this is completed, in step 823, the data saved in step S21 is returned to the accumulator, and the interrupt processing is ended.

Therefore, the subroutine on the RAM is the same as being added to the main routine on the ROM at the location when the interrupt occurs, and there are no restrictions on its content as long as it can be executed.

In other words, the content does not necessarily have to replace the entire program on the ROM as in the past.

Therefore, if you prepare a program in external memory to add to the fixed program in ROM or change a certain part of the fixed program, it will be read into RAM at startup and stored as a subroutine. . Then, a subroutine in RAM is executed instead of the fixed program by a regularly generated interrupt.
Here you can add additional processing or make changes to the fixed program processing. This means that it is possible to make specification changes to the masked program.

Next, a specific example of specification change according to the present invention will be explained.

FIG. 3 is a flowchart showing an example of a case where there is a specification change regarding lighting of the LED.

The program in this figure is on the ROM and the LED ■.

Assuming that a fixed program is stored that specifies that LEDs (2) and (2) are turned on independently, this is a specification change program that causes LED (2) to turn off only while LED (2) is turned off.

First, assuming that the LED ■ is on and the LED ■ is off, the determination in step S31 is YES.

The determination in step S32 becomes No, and in step 833, the LED memory is set to '1m, and the LED ■ is turned off. Here, setting the LED memory to "1" means setting data indicating that since the LED ■ was off, the LED ■ that had been lit was turned off.

When the LED ■ turns on eventually, step S31 is NO1.
The result in step S34 is YES, the determination in step S35 is YES, and the LED is turned on.

■ will light up, and the LED memory will be reset to "0°."

As a result, the lit LED ■ is turned off only while the LED ■ is turned off.

In other cases, the LED ■ is lit first, and when the LED ■ is lit, step S31.832 becomes YES,
The current state will be maintained.

Also, even if the LED ■ is off and the LED ■ is lit, the LED
When the D memory is 0m and the LED ■ has not been turned off by the control of this subroutine,
Step S31 becomes NO, step S34 becomes YES, but step S35 becomes No, and the same state is maintained.

Although a specific example of a change in specifications has been described above, the present invention can also accommodate changes in hardware specifications.

For example, Fig. 4 shows an example of a specification change using hardware. In this figure, A and B are output ports, C is an input port, and output port A is 'L#' and output port B is 'H#'.
The plan is to supply the human-powered boat CE "H" only when

According to the present invention, the step of determining whether or not output port A is 11L II and whether or not output port B is "Ho", and the step of determining whether or not output port A is "Ho", and only when a YES determination is made in both steps, the input port By preparing a program to set C to "Ho" in an external memory, a specification change equivalent to the hardware change shown in FIG. 4 can be achieved.

〔Effect of the invention〕

As explained above, according to the present invention, by preparing a program in the external memory for adding to a fixed program or changing a certain part of the fixed program, it is stored in the internal memory at startup. loaded,
Periodically generated interrupts cause subroutines in its internal memory to be executed instead of the fixed program, where additional processing or changes can be made to the processing of the quantification program. (This means that specifications can be changed and additions made to the standardized program. This provides the following various benefits.

■ By masking the basic program and writing the parts to be changed according to each specification into external memory, there is no need to mask the microcontroller for each specification, and only one type is required.

■ Specification changes can be made on software to replace hardware specification changes that are allocated on the same memory map as the internal memory.

■ By increasing the capacity of the internal memory that can be read and written, there is no limit to the size of additional programs, making it easier to expand functionality.

■ Costs are reduced because masking is not required when adding or changing programs.

■ Furthermore, since there is no need to spend time creating masks for program additions and changes, program additions and specification changes can be made quickly. Incidentally, masking takes about four weeks, but external memory can be completed in one day.

■ Previously, if a specification error occurred, the microcontroller would be thrown away, but now it will be possible to make use of such a microcontroller.

■ Additions and changes to programs do not necessarily require replacing the entire target program, and partial changes can be made, reducing the number of man-hours for software designers.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a process of reading a microcomputer specification change program into an internal RAM according to an embodiment of the information processing apparatus of the present invention. FIG. 2 is a flowchart showing the interrupt processing for executing the loaded program.
FIG. 3 is a flowchart showing a specific example of a specification change according to the present invention, FIG. 4 is a circuit diagram showing an example of a hardware specification change that can be handled by the present invention, and FIG. FIG. 2 is a conceptual diagram of a memory map showing a memory configuration. Sll-S14... Step of confirming the presence or absence of program data in the external memory in response to the activation signal, S15. S16: means for reading the program data from the external memory to the internal memory to form a subroutine when the program data exists in the external memory; A step of stopping the program execution and executing the subroutine in the internal memory.

Claims (1)

[Scope of Claims] A masked internal memory that stores a fixed program, a readable/writable internal memory, a means for confirming the presence or absence of program data in an external memory in response to an activation signal, and the above-mentioned device. means for reading the program data from the external memory into the internal memory to form a subroutine when program data exists in the external memory; means for periodically generating an interrupt signal; and means for periodically generating an interrupt signal; An information processing device comprising: means for stopping execution of the fixed program and executing a subroutine in the internal memory.