JPS62196863A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To rapidly process against a system down due to a defect by providing a judging circuit for comparing input/output signals of a circuit with a result stored in advance in itself to decide a signal to a terminal switching circuit. CONSTITUTION:When a signal is normally applied from an exterior to an input terminal A, it is transmitted through a conductive passage 5 to a circuit 2 and a judging circuit 4. The circuit 2 outputs an output signal responsive thereto through a conductive passage 6. At this time, the judging circuit 4 stores in advance input/output data in a memory. When it judges that the circuit 2 is normal, a close signal is output through a conductive passage 8 to a terminal switching circuit 3, and when it judges to be abnormal, an open signal is output to the circuit 3.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a circuit configuration of a semiconductor integrated circuit.

[Prior art] Conventionally, this type of semiconductor integrated circuit is used mounted on an electronic circuit package, but if even one of them breaks down, the impact is significant, and in most cases, the system will go down. In many cases, reliability is required to be higher than necessary. Moreover, the failure diagnosis requires a large amount of man-hours even if expensive equipment and highly skilled inspectors are used.

[Problems to be solved by the invention] When a large number of conventional semiconductor integrated circuits (LSI) are mounted on a printed circuit board to form a so-called electronic circuit package, a failure of one LSI can cause the entire device to system down. However, since failure diagnosis requires a large amount of man-hours, it takes a long time to recover, and the number of tests is large.Furthermore, it takes a lot of man-hours to completely inspect the package in the package inspection that is required in the intermediate inspection process. It was necessary to improve the situation, which was becoming close to impossible in terms of inspection technology.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor integrated circuit in which a self-judgment function is provided to the circuit itself, thereby making it possible to quickly deal with a system failure due to a failure.

[Means for Solving the Problems] The present invention opens and closes a conductive path between a circuit section, an input/output terminal section, and the circuit section and the output terminal section, and when the operating state is good, the circuit section and an output terminal section, and in the case of no connection, a conduction path between the circuit section and the output terminal section is opened to make all output terminals high impedance, and an input to the circuit section. A judgment circuit unit that compares both the signal and the output signal of the circuit unit in response to the signal with a result stored in the circuit in advance, and determines the signal to be sent to the terminal switching circuit unit based on the result. This is a semiconductor integrated circuit characterized in that it has a semiconductor integrated circuit.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The present invention 1 is composed of a circuit section 2, a terminal switching circuit section 3, input/output terminal sections A and B, a judgment circuit section 4, and an output terminal C that notifies the result of the judgment circuit section 4 to the outside.

Although the terminal switching circuit section 3 is actually composed of a semiconductor element, it is shown here in the form of a simple switch for the sake of simplicity (actually, there are a plurality of them).

Further, reference numeral 5 denotes a conductive path for applying the signals (a plurality of signals) applied to the input/output terminal section A to the circuit section 2 and the judgment circuit section 4. 6 is a conductive path for applying the signals (multiple signals) output from the circuit section 2 to the judgment circuit section 4 and the terminal switching circuit section 3; 7 is a conductive path for applying the signals (multiple signals) output from the terminal switching circuit section 3; ) is applied to the output terminal portion B.

In FIG. 1, when a signal is normally applied to the input terminal section A from the outside, the signal is transmitted to the circuit section 2 and the judgment circuit section 4 through the conductive path 5. The circuit section 2 outputs a corresponding output signal through the conduction path 6. At this time, the judgment circuit section 4 monitors the input signal and output signal to the circuit section 2 through the conductive paths 5 and 6 to monitor whether the circuit section 2 is operating correctly. The judgment circuit section 4 is usually composed of a microcomputer, a memory, etc., and all input signals and correct output signals corresponding to the input signals when the circuit section 2 is used are stored in advance in the memory. The correct output signal for the input of the conductive path 5 is selected from the stored memory, and the quality is determined by comparing it with the value for the input of the conductive path 6. If the result is good, a close signal is sent to the terminal switching circuit section 3 through the conduction path 8, and at the same time, a good signal is sent to the external output terminal C through the conduction path 9. If the result is negative, signals indicating the difference and failure are outputted through the conductive paths 8 and 9, respectively. The terminal switching circuit section 3 is a circuit that has the function of directly connecting the output signal of the circuit section 2 outputted through the conduction path 6 to the conduction path 7 according to the signal of the conduction path 8, or making it high impedance.

The state shown in FIG. 1 is a diagram showing the situation when the circuit section 2 is operating correctly, and the terminal switching circuit section 3 is operated by the signal of the conduction path 8, the conduction paths 6 and 7 are connected, and the circuit This shows a state in which the output of section 2 is directly output to C.

The state shown in FIG. 2 is a diagram showing a situation when the circuit section 2 is malfunctioning, and the terminal switching circuit section 3 is operated by the signal from the conduction path 8, and the conduction paths 6 and 7 are disconnected. This indicates a state in which the impedance becomes high and a negative signal is output to C.

The third example is a diagram showing a case where a plurality of such semiconductor integrated circuits (LSI) are mounted on a circuit board to configure an electronic circuit package 1 having a certain algorithm. In the figure, A and B are input/output terminal parts, and 20 to 27 are LSIs of the present invention.
, 30 to 37 are output terminals indicated by C in FIG. 1 or 2. Further, in this figure, actual input/output signal lines are omitted for simplicity. A as shown by mark @C in Figure 3.
If an ND circuit is configured and its output 40 is sent to the output terminal section B, monitoring whether this electronic circuit package 1 is operating correctly can be done by monitoring the signal line 40 from the system side through B. It is possible. Even if a plurality of such electronic circuit packages are used, the above-described method allows the system to immediately determine which package is defective, thereby greatly reducing system downtime.

Also, during package inspection, which is an intermediate inspection process, since each LSI has a built-in judgment circuit, a huge number of test patterns are applied to check all the algorithms of the electronic circuit package, as in the past. It is not necessary to apply only a very short basic pattern and monitor only the output 40 in FIG.
If the IC is defective, the defective IC can be immediately identified by checking only the signals of terminals 30 to 37, which are the inputs of C.

If package inspection is performed based on this concept, package inspection requires only inspection equipment mainly for the purpose of detecting manufacturing defects, and it is possible to significantly reduce equipment costs and the number of inspectors.

[Effects of the Invention] As explained above, the present invention reduces system down time at the equipment level and improves inspection, which is the biggest bottleneck in package inspection, by incorporating a judgment circuit inside a semiconductor integrated circuit. method.

This method has the effect of simplifying inspection equipment, reducing costs, and shortening failure diagnosis and repair, which can be performed more easily and reliably than conventional methods.

[Brief explanation of drawings]

Figure 1 is a block diagram showing an embodiment of the present invention, Figure 2 is a diagram showing a state in which the circuit section malfunctions and all output terminals are in high impedance, and Figure 3 is the same as Figure 1. FIG. 3 is a diagram showing a state in which a plurality of embodiments are mounted on a circuit board. 1: Semiconductor integrated circuit of the present invention A: Input terminal section B: Output terminal section 2: Circuit section
, 3 = terminal switching circuit section 4: judgment circuit section 5.6, 7.8, 9: conduction path

Claims (1)

[Claims] (1) Open and close the conductive path between the circuit section, the input/output terminal section, and the circuit section and the output terminal section, and simply connect the circuit section and the output terminal section when the operating condition is good. , a terminal switching circuit section that opens the conduction path between the circuit section and the output terminal section and makes all output terminals high impedance when the input signal is input to the circuit section and the output of the circuit section in response to the input signal. A single semiconductor chip is characterized by having a determination circuit section that compares both signals with results stored in the device in advance and determines the signal to be sent to the terminal switching circuit section based on the results. Semiconductor integrated circuit.