JPH02195444A - Method for designing printed board mounted on microcomputer - Google Patents

Abstract

PURPOSE:To easily retrieve a fault and to shorten the debugging time of hardware by separating respective circuits in each block and retrieving the fault. CONSTITUTION:When a fault is generated in a monitor command e.g., a processor block is electrically disconnected from a monitoring circuit 600 by turning off a 1st switch element 800 and the cause of the fault is retrieved in the processor block consisting of a processor 100, a storage circuit 200, a serial conversion circuit 400, and a timing pulse generating circuit 500. When the cause of the fault is not detected in the processor block, the switch element 800 is turned on and a 2nd switch element 900 is turned on to retrieve the cause of the fault in the circuit 600. When the cause of the fault is not detected in the block of the circuit 600, both the switch elements 800, 900 are turned on and an interface circuit 700 is retrieved.

Description

[Detailed description of the invention] [Summary] Regarding the design method of a printed circuit board equipped with a microcomputer used in communication equipment, etc., it is possible to easily detect faults by designing each block to be electrically separable. The purpose of the present invention is to provide a design method for a printed circuit board equipped with a microcomputer that shortens debugging time. It has a processor block consisting of a circuit, a serial conversion circuit that outputs serial data, a timing pulse generation circuit that outputs timing pulses, a monitoring circuit that monitors program operation, and an interface circuit that interfaces for connection with external devices. In a printed circuit board equipped with a microcomputer, first and second switch elements that can be turned on and off are inserted into the bus and control lines connecting the timing pulse generation circuit and the monitoring circuit, and the monitoring circuit and the interface circuit, respectively, and the processor The block and the monitoring circuit, and the monitoring circuit and the interface circuit are configured to be electrically isolated.

[Industrial application field]

The present invention relates to an improvement in a method of designing a printed circuit board equipped with a microcomputer (hereinafter referred to as a microcomputer) used in a communication device or the like.

At this time, there is a need for a design method for a microcomputer-mounted printed circuit board that facilitates failure detection and shortens hardware debugging time by designing each block to be electrically separable.

[Conventional technology]

FIG. 3 is a block diagram showing the configuration of a conventional microcomputer-mounted printed board.

As shown in FIG. 3, a printed board (not shown, dimensions: 20 cm x 30 cm, for example) on which a microcomputer is mounted includes a processor (hereinafter referred to as CPU) 1, a random access memory (hereinafter referred to as RAM) 21. lJ-only memory (hereinafter referred to as ROM) 3, a communication interface section (hereinafter referred to as C1^) that performs parallel/serial conversion of data 4, a programmable timer (hereinafter referred to as C1) that sets the operation cycle of the CIA 5, a watchdog timer (hereinafter referred to as WDT) 6, and an external interface section 7.

Above CPU 1, RAM 2, ROM 3, ^CTA
4 and P2H4 constitute one block (hereinafter referred to as a processor block), which performs the basic operations of the CPU.

The function of the WDT6 is to assign an address in advance and set it so that data can be written at a fixed cycle.When data is written, a counter (not shown) is reset (initialized), and when the writing is completed, the counter starts operating. It starts and outputs an alarm at regular intervals or resets it. This is used for program monitoring. W.D.
T6 is made by combining ICs and constitutes one block.

The external interface section 7 has functions such as converting voltage when connecting another printed board or connecting a thermometer for measuring data, and constitutes one block.

These blocks had an inseparable structure.

[Problem to be solved by the invention]

However, in the above-mentioned printed circuit board configuration, if an initial failure occurs, such as when the monitor commands supplied from the ROM (corresponding to the operating system in a normal personal computer) do not work,
The cause of the failure must be found throughout the printed circuit board.
The problem was that it was difficult and time-consuming to find the cause.

Therefore, an object of the present invention is to provide a method for designing a printed circuit board equipped with a microcomputer, which facilitates fault search and shortens hardware debugging time by designing electrically separable blocks. .

[Means to solve the problem]

The above problem is solved by the configuration shown in FIG.

That is, in FIG. 1, a processor 100, a memory circuit 200, a memory circuit 200, a serial converter circuit 400 that outputs serial data, and a timing pulse that are connected to each other by a bus and a control line and exchange predetermined data and control signals between them. Timing pulse generation circuit 5 to output
00, a monitoring circuit 600 for monitoring program operations, and an interface circuit 700 for connecting with an external device.
0 and 900 are a timing pulse generation circuit and a monitoring circuit;
and first and second switch elements which are inserted into a bus and a control line connecting the monitoring circuit and the interface circuit, and which can be turned on and off, respectively.

The processor block and the monitoring circuit, and the monitoring circuit and the interface circuit are configured to be electrically isolated.

[For production]

In FIG. 1, for example, if a failure occurs in a monitor command, the first switch element 800 is first turned off to electrically isolate the processor block and the monitoring circuit 600, and the processor 100 and the memory circuit are electrically separated. 200
, serial conversion circuit 4 that outputs as serial data
00, the cause of the above failure is searched for in a processor block consisting of a timing pulse generation circuit 500 that outputs timing pulses.

If the cause of the fault cannot be found in the processor block, the cause of the fault can be found in the block of the monitoring circuit 600 by turning on the first switch element 800 and turning off the second switch element 900. Explore.

When the cause of the failure cannot be found in the block of the monitoring circuit 600, the first and second switch elements 8
00.900 are both turned on to search for the cause of the failure in the block of the interface circuit 700.

In this way, by separating each block and searching for the cause of the failure, it becomes easier to search for the failure, and the time required for debugging the hardware can be shortened.

〔Example〕

FIG. 2 is a block diagram showing the configuration of a microcomputer-mounted printed board according to an embodiment of the present invention.

The same reference numerals indicate the same objects throughout the figures.

In Figure 2, between PTM50 and -DT60 and -D
Short bins or switches 80.81 and 90.91 are provided on the bus and control lines connecting the T60 and the external interface section 70, respectively, and between the processor block and the 10 T60 block and +1 DT60 block and the external interface section 70 block. electrically isolated.

Now, when a problem occurs such as the monitor command not working,
First, turn off the switches 80 and 81 to electrically isolate the processor block and the 10T600, and then
A processor block including CPUIO, RAM2
0, ROM 30, ACIA 40, and PTM 50 are checked to see if a failure has occurred. ili! One way to check is to connect a synchroscope (not shown) to the clock terminal of the CPU made with LSI and check the presence or absence of the clock. (2) Connect a terminal device (not shown) to ACIA 40 and check the operation of ACIA 40 and PTM 50. Also, it is checked whether access to the ROM 30 is being performed normally.

If no fault is found in the processor block cputo-PTM50, switch 80.81 is turned on and switch 90.91 is turned off to check whether or not a fault has occurred in the block 10T60. Specifically, a synchroscope, a logic analyzer, etc. are connected to the output terminals (multiple terminals), clock terminal, etc. of the WDT 60 for observation. Furthermore, it is checked by accessing with a monitor command and writing/reading data.

When no fault is found in the WDT60 block,
Switches 80.81 and 90.91 are both turned on to check whether or not a failure has occurred in the block of external interface section 70. Here, as in the case described above, a synchroscope, logic analyzer, etc. are connected to the output terminals (plurality), clock terminals, etc. of the external interface section 70 made of an IC, and the investigation is performed. Furthermore, it is checked by accessing with a monitor command and writing/reading data.

In this way, the printed board hardware is debugged.

As a result, by electrically separating each block and searching for a fault, it becomes easier to search for a fault, and the time required for debugging the hardware can be shortened.

〔Effect of the invention〕

As described above, according to the present invention, by separating each block and searching for a fault, it becomes easy to search for a fault, and the time required for debugging the hardware can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a block diagram showing the configuration of a microcomputer-mounted printed board according to an embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of a conventional microcomputer-mounted printed board. . In the figure, 800 indicates a first switch element, and 900 indicates a second switch element. Structure and block diagram shown in Figure 2. Conventional Ida j's Mycosine and Burisitone trees with one person and a block diagram with dimensions.

Claims (1)

[Claims] A processor (100) that is connected to each other by a bus and a control line and that exchanges predetermined data and control signals between them, a storage circuit (200), and a serial conversion circuit that outputs serial data ( 400), a timing pulse generation circuit (500) that outputs a timing pulse
A microcomputer-mounted printed board having a processor block consisting of a processor block, a monitoring circuit (600) for monitoring program operation, and an interface circuit (700) for interfacing with an external device, the timing pulse generating circuit and the monitoring circuit comprising: First and second switch elements (800 and 900) that can be turned on and off are inserted into the circuit, and the bus and control line connecting the monitoring circuit and the interface circuit, and the processor block and the monitoring 1. A method of designing a printed circuit board equipped with a microcomputer, characterized in that a circuit, and a monitoring circuit and an interface circuit can be electrically separated.