JPH0210439A - Printed board diagnosing system - Google Patents

Abstract

PURPOSE:To execute diagnosis with a high rate at a high speed by providing an input turning-back means, a self-diagnosing means, and an output turning- back means correspondingly to each logic element and selectively performing input turning-back diagnosis, internal diagnosis, and output turning-back diagnosis for each logic element in accordance with diagnostic information. CONSTITUTION:Input turning-back means 10 and 11, self-diagnosing means 32, 33, and 34, and output turning-back means 14 and 15 or 16 and 17 for each logic element 3 are provided correspondingly to each logic element (processor) 3. Diagnostic information 1 is provided which includes at least the logic element number of the diagnosis object, the diagnosis route number, designation of self-diagnosis of the logic element, input/output turning-back information of diagnostic information, and test data. Each of plural logic elements 3 mounted on a printed board 1 is selectively subjected to input turning-back diagnosis, internal diagnosis, and output turning-back diagnosis repeatedly by diagnostic information 1 to diagnose the entire printed board 1.

Description

[Detailed Description of the Invention] [Summary] Regarding a diagnostic method for a printed board on which a plurality of logic elements, such as a microprocessor sensor, etc. are mounted, a plurality of highly integrated elements (I
The purpose of this test is to quickly and accurately perform functional diagnosis of the internal circuits of C, LSI) and the internal circuits 1 and peripheral circuits of microprocessors. A folding means, a logic element self-diagnosis means, an output folding means, and at least a logic element number 9 to be diagnosed.
Diagnosis route number, logic element self-diagnosis designation 9 Diagnosis information input, output return designation information, and diagnostic information including test data (password) are provided for multiple logic elements mounted on a printed board. The input side loop diagnosis, logic element internal diagnosis, and output loop diagnosis are selectively repeated for each logic element in a specific order based on the above diagnostic information, thereby diagnosing the entire printed board. Configure.

[Industrial application field]

The present invention relates to a method for diagnosing a printed circuit board on which a plurality of logic elements, such as a microprocessor, are mounted.

With the recent trend towards higher integration of logic elements, the logic elements mounted on printed circuit boards are now equipped with multiple logic elements with complex functions such as micro-prosensors. It has become impossible to input physical-level data into the input terminals of a printed board and use the response result data to diagnose the normality of the internal circuit of the printed board. In addition, there is a need for a diagnostic method that can diagnose the normality of a printed circuit board in a short time even if it is equipped with a logic element having a complicated function.

[Prior art and problems to be solved by the invention] FIG. 4 is a diagram illustrating a conventional diagnostic method for printed circuit boards.

Conventionally, in a unit test of a printed board 1 using an integrated circuit (IC), a highly integrated circuit (LSI), etc., a plurality of pieces of diagnostic information are combined from the input connector pin 1a of the printed board 1, and the Diagnosis was performed by inputting the input to the internal circuit of the board 1 and taking out the output result of the internal circuit from the output connector pin 1b of the printed board 1.

In this conventional diagnostic method, diagnostic data at a specific physical level is input according to the configuration of the internal circuit of the printed board 1, and the operation of the internal circuit 3 of the printed board 1 is checked.

However, due to the recent high integration of logic elements 3, improved packaging density on the printed circuit board 1, and mounting of various microprocessors, it is now possible to combine diagnostic data at the physical level from the input connector pin 1a of the printed circuit board 1. It has become difficult to diagnose printed circuit boards equipped with these logic elements 3.

For example: (1) If you try to increase the diagnosis rate, the diagnosis time will increase.

(2) In the physical level diagnostic database, the internal circuit of the high-density highly integrated circuit (LSI) 3.

It is virtually impossible to diagnose the internal circuits of the microprocessor, and the scope of diagnosis is limited to the area around the interfaces of these logic elements 3.

(3) Even if a fault is detected, it is difficult to obtain diagnostic data necessary to isolate the fault location, and the time required to investigate the fault location becomes long.

There were other problems.

Due to these circumstances, the conventional diagnosis method using diagnostic data at the physical level is
I) It has become impossible to diagnose the printed circuit board 1 equipped with a microprocessor 3 and the like.

In view of the above-mentioned conventional drawbacks, the present invention provides a highly integrated circuit (LSI).
Highly integrated circuits (LSI) are used to diagnose printed circuit boards equipped with high-performance logic elements such as microprocessors.
, microprocessors, etc. have advanced functions and self-diagnosis functions, and the object of this invention is to provide an effective diagnosis and fault isolation method.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle of the printed board diagnosis method of the present invention.

The above problems are solved by a printed circuit board diagnosis method configured as follows.

This is a diagnostic method for a printed board l on which a plurality of logic elements 3 are mounted, in which input return means (10, 1
1), self-diagnosis means 32, 33, 34 of the logic element 3, and output folding means 14, 15. Or 16.17.

At least, the number of the logic element to be diagnosed 9 the diagnosis route number, the self-diagnosis designation of the logic element 1 the input of diagnostic information, the output return designation information, and the diagnostic information (2) including test data (password) are provided and mounted on the printed circuit board 1. For a plurality of logic elements 3, input-side wrap-around diagnosis is performed using the above-mentioned diagnostic information (2) for each logic element 3.

The configuration is such that the entire printed circuit board 1 is diagnosed by repeating selectively performing the internal diagnosis of the logic element 3 and the output return diagnosis.

[Effect]

That is, according to the present invention, in a method for diagnosing a printed circuit board on which a plurality of logic elements, for example, a microprocessor, etc. are mounted, first, as diagnostic information input from the outside, information that limits the diagnostic range is used; Using this diagnostic information, it is possible to selectively diagnose each logic element mounted on the printed board, such as a microprocessor.

In addition, in order to be able to perform functional diagnosis of the high-density highly integrated circuit (LSI) mounted on the printed board, the internal circuit of the microprocessor, and its peripheral circuits,
A self-diagnosis means is provided, and diagnosis information from the outside can be used to activate the self-diagnosis means and to instruct writing of the self-diagnosis results to an output register.

In addition, each logic element, for example, a microprocessor, has an input register (INLET LOOP) for diagnostic information.
Loopback, output register (OIITLET LOOP)
It has a loopback mechanism and can be specified using the above-mentioned external diagnostic information.

The information that limits the scope of diagnosis in the above diagnostic information includes the processor number to be diagnosed, the route number indicating the sequential diagnosis route, the designation of microprocessor self-diagnosis, and the manual register (INLET LOOP) of the diagnostic information. Specified 1 diagnostic information output register (OUTLET)
LOOP) loopback designation, startup/result information includes, for example, startup bit, return bit (bit to be turned on at the end of diagnosis), test data (pig for communication with each microprocessor: password), etc.

First, in the order of diagnosis, input register loopback diagnosis is performed with the input register rlNLET LOOPJ loopback designation of processor patient 1, and it is confirmed whether the expected diagnostic information is returned.

Next, start the processor diagnosis of processor Nll with a self-diagnosis instruction, and send the diagnosis result to the output register on the input side.
Check by outputting to (OUTLET LOOP).

Next, the output register rOUTLETL of processor floor 1
Perform loopback diagnosis of the output register with OOI'J loopback specification and check whether the expected diagnostic information is returned. At this time, the configuration is such that the diagnostic information can pass through the processor &1.

Next, input register rlN of processor No. 2
LET LOOPJ return confirmation, processor diagnosis of processor 2, and its output register rOU
TLET LOOP J Check back.

In this way, the diagnostic results are sequentially output to the output register (OUTLET LOOP register) at the operating speed of each processor, and the diagnostic results are outputted at high speed along the specified diagnostic route.
Printed board diagnostics can be performed.

Therefore, in recent years, diagnosis has become difficult, such as unit testing of printed circuit boards equipped with high-density, highly integrated circuits (LSI), and highly functional microprocessors, or equipment testing.
By adding some diagnostic circuits to the chip etc., it becomes possible to execute the test at higher speed and with a higher diagnostic rate, which is effective in improving product quality and reducing costs.

〔Example〕

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

The above-mentioned FIG. 1 is a diagram showing the principle of the printed board diagnosis method of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention.
(a) shows an example of the configuration of a printed board, (b) shows diagnostic information 9
An example of the format of diagnosis result information is shown in FIG. 3, which is a diagram illustrating an example of a self-diagnosis mechanism of a processor. Processor self-diagnosis means 33, 34
．． 35 (see Figure 3), output register (OUTLET
LOOP) folding means 14.15. Or 16, 17
The diagnostic information (2) and the diagnostic result information (2) are necessary means for carrying out the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

Hereinafter, the printed board diagnosis method of the present invention will be explained with reference to FIGS. 1 and 2.

In this embodiment, for convenience of explanation, processor (1)
~(4) For 2, root (1?0IJTE) (
1) , (2) Connect the diagnostic routes, Rou) (R
Diagnosis from (1) and route (ROUTE)
) Cases in which diagnosis can be made from (2) are shown.

First, in order to realize the printed board diagnosis method of the present invention,
Each chip (or highly integrated circuit) mounted on the printed board 1
The internal structure of the LSI (LSI) or microprocessor (3) must have the configuration shown in FIGS. 2(a) and 3.

That is, the input registers (INLET LOOP) 10, 15, which connect each chip 3 in FIG. 2(a).
1? , Output register (OUTLET LOOP) 11
, 14, 16, and self-diagnosis mechanisms 33-34 for the circuit 35 in the chip 3 shown in FIG.

Built-in circuits like this are becoming more and more popular due to the recent trend towards ultra-high integration.
In particular, it has not become a factor that hinders the present invention.

In FIG. 2(a), a plurality of processors (1).

The printed board diagnostic method consisting of (2), (3), and (4) will be specifically explained below.

In the case of this example, if (ROIITE) (1) is specified ((b) In the diagnostic information ■ in the figure, r
5TARTROIJTE ltJ rRETURN
(can be specified by ROUTE Nol), the order of diagnosis is processor (1) facing processor (2) → processor (3).
)=O processor (4).

Each processor 3 checks the contents of the diagnostic information (see FIG. 2(b)) and sequentially registers the output register (OUTLET LOOP) 11° or 14. according to the specified route l1m. Alternatively, the diagnostic information ■ is passed to 16.

At this time, each processor 3 is a test chip for the diagnostic information? If k (TEST CIIIP No.) matches its own processor size, it executes diagnosis and passes the diagnosis result to the return route (r RETLIRN ROUTEN No., specified by J).

For example, if the input side loop diagnosis designation for chip size "1" (i.e. rINLBT LOOPJ of diagnostic information
1'), input register x (IN+, HT L
It functions to return the diagnostic information input to the output register (OUTLETLOOP) 11 to the output register (OUTLETLOOP) 11.
Processor diagnostic designation (i.e. diagnostic information (7) rDI
When AG TEST J is l'), the processor self-diagnosis results described later are output to the output register (OUTLET L).
OOP) Functions to return to 11.

In addition, output side return diagnosis designation (i.e. rO of diagnostic information
If UTLET LOOP J is T), the diagnostic information input to output register (OUTLET LOOP) 14 is input to input register (INLET LOOP) 1.
5, the output register (OUTLET LOOP
) It operates to return to 11. In this case, the diagnostic information (2) bypasses the processor 3.

When diagnosing the processor (2) 3, the diagnostic information (2) bypasses the chip at the chip level '1' and is then captured at the chip level '2', and the diagnosis is performed in the same manner as above.

Similarly, when rsTART ROUTE mJ TELUT (1?011TE) (2) is specified, the diagnosis order is as shown in Figure 2 (a): Processor (1) = + Processor (4) = + Processor (3) = 6 processors (2).

These two route specifications make the diagnosis more accurate,
When a failure is detected, information on the location of the failure is provided as information including the physical location based on the configuration of the printer B&, making it easy to process the location.

Next, the self-diagnosis operation in each chip will be explained with reference to FIG.

First, the LOOP control circuit 32 is activated by the diagnostic information input to the input register (INLETLOOP) 10, and if the diagnostic information is not for this processor, the output register (OUTLET LOOP) ) 14. Alternatively, the diagnostic information ■ is transferred (bypassed) to the next processor via 16, but it is the diagnostic information ■ for this processor (1) and also provides a self-diagnosis instruction (DIAG TF! S
If it is recognized that T) has been instructed, an interrupt is made to the processor 33 and the self-diagnosis mechanism 34 of the processor 33 is activated.

The diagnostic program of the self-diagnosis mechanism 34 is located on a read-only memory (ROM) or a control storage.
In this case, the information is downloaded from an external storage device (not shown) in advance, such as when the power is turned on.

By executing the diagnostic program, the processor 33 performs a predetermined self-diagnosis, and outputs diagnostic result information to the register (OtlTLET LOOP) 11.
You can respond via .

With this configuration, it is possible to sequentially execute the diagnosis of three units of chips, for example, processors (1) to (4), and the output diagnosis result information (error detection in Figure 2 (b) (See chip Na (ERRORDETECTED), error code (ERRORC0DE), etc.) makes it possible to identify the location of the failure.

In the diagnostic information (2) shown in FIG. 2(b), the test data (TEST DATA) is the password for the chip (logic element) 3 to be diagnosed, as described above, and is For example, when the test data (password) rAAJ comes in, it is recognized as correct diagnostic information and rERRORC0D of the diagnostic result information
By returning a password of "55" indicating normal completion to EJ, it is possible to confirm the transmission and reception of the diagnostic information (2).

In addition, in the diagnostic information ■, rSTART J is set to ``on'' when starting the diagnosis, and rRETURN J is set to ``on'' when the specified diagnosis is completed. rERRORJ turns "on" when an error is detected in the diagnostic operation, so when this instruction is recognized, the aforementioned rERRORC0DEJrER
The location of the failure can be identified by looking at the "RORDETECTED CHIP floor".

As described above, the present invention is capable of diagnosing a printed circuit board on which a plurality of highly functional chips such as highly integrated circuits (LSIs) and microprocessors are mounted. It is equipped with an input/output register, a folding means for the input/output register, and a self-diagnosis mechanism for the circuit within the chip. For example, repeating the circuit self-diagnosis of the output side register and outputting the respective diagnosis result information for each route, completes the diagnosis of all chips on the printed board, and outputs the diagnosis result information. The feature is that the failure location can be easily identified based on the following information.

〔Effect of the invention〕

As described above in detail, the printed board diagnostic method of the present invention is a method for diagnosing a printed board on which a plurality of logic elements, such as microprocessors, etc. are mounted. Corresponding to the logic element,
Input wrapping means.

Self-diagnosis means for logic elements and output folding means.

At least the logic element number 9 to be diagnosed;
Logic element self-diagnosis designation 1 Diagnostic information input, output return designation information, and diagnostic information including test data (password) are provided, and multiple logic elements mounted on a printed circuit board can be checked in a specific order. , For each logic element, input side loop diagnosis and internal diagnosis of the logic element are performed based on the above diagnosis information.

The system is designed to diagnose the entire printed circuit board by repeatedly performing output loop diagnosis selectively, so it can be used for high-density, high-integration circuits (LSIs), which have recently become difficult to diagnose. Unit testing of printed circuit boards equipped with functional micropro sensors.

Alternatively, by adding some diagnostic means to a chip or the like, device testing can be performed faster and with a higher diagnostic rate, which is effective in improving product quality and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the printed board diagnosis method of the present invention. FIG. 2 is a diagram showing an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a self-diagnosis mechanism of a processor. FIG. 4 is a diagram illustrating a conventional printed board diagnosis method. In the drawing, 10 is the input side manual register (INLET LOOP)
. 11 is the input side output register (OUTL[!T LOO
P). 14.16 is the output register (OIITLET) on the output side.
LOOP). 15.17 is the input register on the output side (INLET LO
OP). 3 is a processor (1) to (4), a logic element, an integrated circuit (IC), a highly integrated circuit (LSI), or a chip. 32 is a LOOP control circuit, and 33 is a processor. 34 is a self-diagnosis mechanism (a read-only memory (ROM) that stores a diagnostic program and a function program for each chip);
, control storage) 35 is a unique circuit for each chip. ■ is diagnosis information, ■ is diagnosis result information. ROUTE (1) and (2) are diagnostic routes. Birdwatch Ryokuni

Claims (1)

[Claims] A printed board (on which a plurality of logic elements (3) are mounted)
1), which includes an input looping means (10) corresponding to each logic element (3).
, 11) and self-diagnosis means (32, 3) for the logic element (3).
3, 34) and output folding means (14, 15, or
16, 17), and diagnostic information ([1]) including at least the logical element number to be diagnosed, diagnostic route number, logic element self-diagnosis designation, diagnostic information input, output return designation information, and test data (password). and for each logic element (3) in a specific order, based on the above diagnostic information ([1]), for a plurality of logic elements (3) mounted on the printed board (1), By repeating selectively performing the input side loop diagnosis, the internal diagnosis of the logic element (3), and the output loop diagnosis,
A printed board diagnostic method characterized by diagnosing the entire printed board (1).