JPH04205359A - Program rom erroneous packaging detecting system and program rom function switching system - Google Patents

Abstract

PURPOSE:To automatically detect an erroneous packaging state by writing an instruction which executes prescribed alarm processing on an area starting with a fetched erroneous start address when a program ROE is packaged erroneously. CONSTITUTION:When the program ROMs 12, 13 are packaged at reverse positions, (0406h) is fetched from the area (1) of a fixed address as a start address after reset, and a microprocessor 11 starts the processing from that address. Therefore, the operand and data of a control program to inform the reverse packaging of the program ROMs 12, 13 to the outside are written on an area (2) starting from (0406h). Also, when the instruction to instruct, for example, the lighting of a lamp is used as the operand, the reverse packaging of the program ROMs 12, 13 can be informed to the outside by putting on the lamp. In such a way, the erroneous packaging can be automatically detected.

Description

[Detailed Description of the Invention] [Summary] Regarding a program ROM erroneous mounting detection method for detecting a mounting error of a program ROM in a microprocessor, it automatically detects that a plurality of program ROMs are not mounted in the correct position. A microprocessor with a predetermined data bus width is connected to multiple program ROMs with a smaller data bus width.
In a system in which the program ROMs are connected in parallel, and the mounting position of each program ROM is determined in advance with respect to the data bus, and a start address is supplied to the microprocessor by combining them, when the mounting position of each program ROM is not normal. A program ROM in which instructions for executing predetermined alarm processing are written is provided in an area corresponding to an erroneous start address fetched by the microprocessor.

[Industrial application field]

The invention according to claim 1 provides a program RO for detecting a mounting error of a program ROM in a microprocessor.
This article relates to a method for detecting M incorrect mounting.

The invention according to claim 2 relates to a program ROM function switching method that uses a combination of data supplied according to the mounting position of a plurality of programs R0M for function selection.

[Conventional technology]

A microprocessor with a predetermined data bus width a has a plurality of microprocessors with a smaller data bus width n (a=nb)
In a system in which program ROMs are connected in parallel and programs and data are supplied by a data bus width a, the mounting positions of the plurality of program ROMs are specified for the microprocessor.

FIG. 3 is a diagram showing a system configuration corresponding to two program ROMs.

In the figure, a microprocessor 31 having a data bus width 2a and two program ROMs 32 and 33 each having a data bus width a are connected via a data bus 34 and an address bus 35. Here, each program ROM 32, 33 has an upper and lower positional relationship with respect to the microprocessor 31. In addition, each program ROM 32, 33 contains the upper side of the start address when the microprocessor 31 is reset.
A'' and lower side r13J are held in each start address storage area of fixed address ``0''.

After the microprocessor 31 is reset by power-on or other means, the microprocessor 31 fetches a start address (address AB) from the start address storage area of the program ROM 32, 33 via the data bus 34, and starts the program or data from that start address. Processing is executed while fetching one after another.

[Problem B to be Solved by the Invention] By the way, the upper and lower positional relationship of the program ROMs 32 and 33 is determined by the mounting position on the printed circuit board. Therefore, it is not uncommon for the microprocessor 31 to be incorrectly implemented in the opposite manner, in which case the microprocessor 31 would fetch the BA address as the start address, which could cause the program to run out of control or cause other abnormalities.

Furthermore, in the configuration shown in FIG. 3, it was necessary to use an external switch or other hardware to switch the execution mode of the program.

The present invention provides a program ROM erroneous mounting detection method that can automatically detect that a plurality of program ROMs are not installed in the correct position, and a program ROM function switching method that can easily switch execution functions. The purpose is to provide.

[Means to solve the problem]

The invention according to claim 1 provides a microprocessor having a predetermined data bus width, in which a plurality of program ROMs having a smaller data bus width are connected in parallel, and each program ROM is mounted at a position relative to the data bus. In a system for supplying a start address to the microprocessor by combining them and determining the start address in advance, the system corresponds to an incorrect start address fetched by the microprocessor sensor when the mounting positions of the respective programs J and ROM are not normal. Claim 21, characterized in that a program ROM in which an instruction for executing a predetermined alarm process is written is provided in a region of the data bus. A plurality of program ROMs having a smaller data bus width are connected in parallel (7) The mounting position of each program ROM is determined in advance with respect to the data bus, and these are combined to supply a start address to the microprocessor. In the system Q, instructions for executing predetermined functions are written in areas corresponding to respective start addresses that are notched by the microprocessor in accordance with the mounting positions of the respective program ROMs. It is characterized by being equipped with a ROM.

[For production]

The invention according to claim 1 automatically corrects the erroneous mounting state by writing in advance a command to execute a predetermined alarm process in an area starting with an incorrect start address that is fetched when the program ROM is erroneously mounted. can be detected. Furthermore, since the operation of the microprocessor is guaranteed, runaway can be prevented from occurring.

The invention according to claim 2 provides a special program by simply writing a program and data for realizing the corresponding functions into an area starting from a start address that is fetched by the microprocessor according to each mounting position of the program ROM. You can switch between multiple functions without any hardware.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the same drawings.

FIG. 1 is a diagram illustrating a first embodiment of the present invention. Note that this embodiment is an example in which incorrect mounting of two program ROMs is detected.

In the figure, the microprocessor 11 has a data bus width of 16 bits and has a program ROM (for example, EE
The PROMs 12 and 13 each have a data bus width of 8 bits and are connected via a data bus 14 and an i-res bus 15. In addition, each program ROM12.
13 has an upper and lower positional relationship with respect to the microprocessor 11.

In addition, each program ROM 12.13 contains a start address rO when the microprocessor 11 is running.
604,, (0000011000000100) J
Among them, the upper side r06. (0000011
, 0) J and lower side' 04 h (000001
00)'' is held in the area ■ of a fixed address (for example, 'Oh J).

Here, if the program ROM 12.13 is installed in the normal position (program ROM 12 is on the upper side),
Seven nodes later, '0604b, + is fetched as the start address from the fixed address area ■, and the microprocessor 11 fetches programs or data one after another from the area ■ starting from the start address I.
The process will be executed while

On the other hand, if the program ROMs 12 and 13 are installed in the opposite location (the program ROM 12 is on the lower side), '0406b' is fetched as the start address from the fixed address area after reset, and the microprocessor 11 is executed at that address. Start processing from. Therefore, in this embodiment, the operands and data of the control program for notifying the outside of the reverse implementation of the program ROM 12.13 are written in the area (starting from 0406hJ).The operands of the control program are used to instruct, for example, lighting of a lamp. If the command is to do so, the reverse mounting of the program ROM 12, 13 can be notified to the outside by lighting the lamp.

In this way, by setting a control program that performs predetermined alarm processing in the area (■) starting from the address that is erroneously fetched in reverse implementation of program ROM 12.13, incorrect implementation can be automatically detected. I can do it. However, each program ROM 12.
It is necessary to determine the value of the start address that will be set to the fixed address 3.

FIG. 2 is a diagram illustrating a second embodiment of the present invention. Note that this embodiment is an example in which incorrect mounting of four program ROMs is detected.

In the figure, microprocessor 21 has a data bus width of 32 bits, and program ROMs 22-25 each have a data bus width of 8 bits, and are connected via a data bus 26 and an address bus 27. It should be noted that the program ROM 22 is located at the top and the program ROM 25 is located at the bottom with respect to the microprocessor 21, and the mounting positions are A, B, C, C, B, C, etc. in order from the top.
Let it be D. Also, of the 32-bit address, the upper 8
The configuration is such that the bits are ignored and the lower 24 bits are valid. (a) shows a state in which each of the program ROMs 22 to 25 is mounted in a regular position.

When the start address indicating the storage address of the regular program and data is "000204h", the fixed address "0." area of each program ROM 22 to 25 has "06k", 'OOh', and "02.", respectively. ”,
"04□" is set. In addition, the program ROM22
The highest start address '06h' set in is ignored.

Here, there are 24 combinations of mounting positions for each of the program ROMs 22 to 25, and 23 combinations excluding the regular mounting positions.
Irregular start addresses will occur if the implementation position is correct. i.e. '06hr', '00h', '02
h”, '04h, and 1, each of which has 1 byte of data, the upper 1
The start address generated by ignoring the bytes has a minimum value of roo0204,'' and a maximum value of r060402h.
This range includes 23 irregular start addresses.

Therefore, an illegal processing section 28 is provided in the program ROMs 22 to 25 to perform alarm processing corresponding to 23 types of incorrect mounting patterns, and branches to the corresponding illegal processing section 28 for each of the 23 irregular start addresses. Write down the command to do so. Therefore, if the program ROMs 22 to 25 are installed incorrectly and the fetched start address becomes an irregular start address, the corresponding illegal processing sections 28 are activated and can issue a predetermined alarm.

Figure 2 (b) shows the program ROM 24 and program R.
This shows a state in which the mounting position of the OM25 is reversed.

Here, since the start address is '000402hJ, the process branches to the corresponding illegal processing section 28 according to the instruction set at that address. Note that by associating each of the 23 irregular start addresses with the illegal processing sections, it becomes easier to identify incorrect mounting patterns.

In addition, each program ROM22 to 2 can store regular programs.
5, programs and data are prevented from being written to the 23 irregular start addresses where branch instructions are set and the illegal processing section that performs predetermined alarm processing.

The above-described invention according to claim 1 detects erroneous mounting at a normal mounting position and avoids runaway during erroneous mounting, but by actively utilizing a plurality of mounting patterns, It can be used for switching functions.

That is, in the area starting from the irregular start address in the above-described embodiment, a program and data that implement a function different from the function stored in the area starting from the regular start address are written. Therefore, by simply changing the mounting position of the program ROM, the corresponding functional programs can be executed.

〔Effect of the invention〕

As described above, in the invention set forth in claim 1, it is possible to easily recognize whether or not the mounting positions of a plurality of program ROMs are correct, and to prevent runaways and other abnormalities due to incorrect mounting. be able to.

In the invention as set forth in claim 2, since the function switching of the program ROM can be designated by the mounting position, the processing becomes easy and hardware and other special external functions can be made unnecessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a first embodiment of the invention according to claim J. FIG. 2 is a diagram illustrating a second embodiment of the invention according to claim 1. FIG. 3 is a diagram showing a system configuration corresponding to two program ROMs. 11...Microprocessor, 12.13...Program ROM, 14...Data bus, 15...Address bus, 21...Microprocessor, 22-25
...Program ROM, 26...Data bus, 27
...Address bus, 2B...Illegal processing section, 31...Microprocessor, 32.33...
・Program ROM, 34...Data bus, 35...
・Address bus. Embodiment 1 of the invention as claimed in claim 1 FIG. 2 Embodiment 2 of the invention as claimed in claim 1

Claims (2)

[Claims] (1) A plurality of program ROMs having a smaller data bus width are connected in parallel to a microprocessor having a predetermined data bus width, and the mounting position of each program ROM with respect to the data bus is determined in advance. A system for supplying a start address to the microprocessor by combining the following, when the mounting position of each program ROM is not normal, predetermined alarm processing is performed in an area corresponding to an incorrect start address fetched by the microprocessor. A program ROM mounting error detection method comprising a program ROM in which instructions to be executed are written. (2) A plurality of program ROMs having a smaller data bus width are connected in parallel to a microprocessor having a predetermined data bus width, and the mounting position of each program ROM with respect to the data bus is determined in advance. In a system for supplying a start address to the microprocessor by combining the following, an instruction for executing a predetermined function is provided in an area corresponding to each start address fetched by the microprocessor according to the mounting position of each program ROM. A program ROM function switching method characterized by having a written program ROM.