JPS62278473A - Semiconductor electronic circuit - Google Patents

Abstract

PURPOSE:To enable inspection with a relatively simple circuitry, by dividing an internal circuit of a semiconductor electronic circuit into several circuits to detect and judge power source currents from the divided circuits. CONSTITUTION:Circuits 2A-2Z have a common ground point 1B and a pair of power source side terminal thereof are connected to switches 3A-3Z, the other ends of which are connected to a current detection circuit 4. A power source 1 for providing voltage and current to the circuits is connected between a ground point 1A and the circuit 4. Respective signals are provided to the switches 3A-3Z from a control circuit 5 while a signal of the circuit 5 is provided to the circuit 4. Here, for example, when the operating condition of the circuit 2A is inspected, the switch 3A alone is closed by a control signal from the circuit 5 while the other switches 3B-3Z are kept open. Under such a condition, the circuit 2A is put into operation and the current flowing through the circuit 4 at that time is checked. This enables judgement on whether the circuit 2A operates normally.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Industrial application field] The present invention relates to semiconductor electronic circuits.

[Conventional technology]

Regarding LSI construction methods that take conventional testing and diagnosis into consideration, as shown in the Journal of the Institute of Electronics and Communication Engineers, 6/81, p. 617, "Testing Machines and Testing Techniques for Ultra-LSIs," tests can be easily carried out inside LSIs. A method has been adopted in which circuits such as these are added in a cumulative manner. A typical example of this method is the scan path method.

An additional circuit that does not affect the original logic function is installed in front of all the flip-flops of the αL8Iffi. By operating these 7 flip-flops as a shift register when performing a functional test, the LSI under test ( This method facilitates testing by equivalently dividing sequential circuits into combinational circuits.

[Problems to be Solved by the Invention] The scale of the circuit for the above-mentioned prior art test is large, and it is difficult to easily diagnose which part of the circuit is in a faulty state.

An object of the present invention is to propose a semiconductor electronic circuit in which the internal circuit of riL3I can be divided into several parts for testing and diagnosis.

[Means for solving problems]

For the above purpose, the internal circuit of the LSI is divided into several circuits,
This is achieved by detecting and determining the power supply 11fi of those circuits.

[Effect]

In other words, by dividing an LSI circuit into several circuits and detecting and observing the power supply current, a unique current flows when the circuit operates, so this judgment can be used to test and diagnose the relevant circuit. can.

Figure 1 shows the principle of the present invention. Circuits 2A and 2B.

..., 2Zt:I has a common grounding point IB, and switches 3A, 3B, ..., 3Z are connected to the power supply @ terminal of the pair.
are connected to the other end of the switch and connected to the t-current detection circuit 4.

A voltage source 11 (usually represented by a battery, etc.) that provides voltage and current to the circuit is applied between the ground point IA and the detection circuit 4. Switches 3A, 3B..., 3Z have a control circuit 5
The signals from the control circuit 5 are also provided to the detection circuit 4.

Now, when checking the operating status of two circuits, switch 3A
Only one switch is closed by a control signal, and the other switches are left open. In this state, voltage #1 is applied only to the two circuits, and the other circuit 2B.

. . ., all are turned off at 2Z. In this state, circuit 2
To put a person in an operating state, it is best to give a signal such as a clock pulse to the two circuits from the outside, or give a signal by coupling means such as magnetism or light)
By checking the current flowing through the t-current detection circuit 4 at that time, it can be determined whether or not the two circuits are operating normally.

When inspecting the circuit 2B, the above operation may be performed with only the switch 3B closed and the other switches opened. This can be done by changing the output signal of the control circuit 5 to open and close this switch.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to Figure @2. In the figure, parts with the same function as the main parts in Figure 1 are given the same numbers.
In this example, they correspond to the gate circuit 13 and the circuit 2B frame flip-flop circuit 14, respectively. switch 3A,
3B is a metal oxide film field effect transistor (hereinafter abbreviated as MOS transistor) 38 people and 30B are used. Current detection can be achieved by connecting resistor 7 in series with voltage source 1 and detecting the voltage across the resistor. ). This detected voltage vla determination circuit 6
sent to. The control circuit 5 includes a counter 8 and a decoder 9, and the counter 8 has an input terminal 10.

! ! FIG. 3 shows typical waveforms of each part in the embodiment of FIG. 2. A clock pulse CP1i is applied to the input terminal 11. This is a carry pulse given to the signal 81n terminal IO, and each time this pulse arrives, the contents of the counter 8 increase (or decrease) by 1, and the output signals Gl, G of the decoder 9
2 changes.

These are currents flowing through the signal 1iti2rt gate circuit 13 and the flip 7a block circuit 14, respectively.

At time to, the content of the counter 8 is O, and at this time, the outputs Gl and G2 are both at 0 level (OV) and %
When the switches 30A and 308rX are off, they are in an open state. Therefore, at this time, ttv and aO flowing in the circuit, and the signal v
1, the current flowing through the a circuits 13 and 14 is expressed as tl. When one calipulse S1 is added at time tl, the counter increments its contents by 1, and the signal Gl becomes level (several V).
), and the switch 30A is closed. As a result, the circuit 13 operates, and the electric current Rit flows through the resistor 7, which becomes voltage v1 and is sent to the determination circuit 6. The determination circuit refers to the signal from the counter 8 and determines whether the current 11 is in circuit 1 or not.
It is determined whether the current waveform is normal operation (in the case of a gate circuit, a pulse current 11 in the figure flows in synchronization with the clock) and a pass/fail determination signal NG is generated.

Time t! When a cali pulse of @2 is added at , now [t
02 becomes Lebel instead of lG IK and switch 30B
is closed. Therefore, after time t2, flip 7
A current iz (172 pulses in synchronization with the clock signal CPI in a lachrymal shape) peculiar to the a-tub circuit flows through the resistor 7 and is judged by the judgment circuit 6.

However, in this case, the clock pulse CPI is
Since it is not given to the flip 7a knob 14 through 3,
It is necessary to give this pulse in a separate platen. For example, if the wiring indicated by the dotted line in the figure is done, another clock pulse CP2
It is a means of giving.

This embodiment has the advantage that it can be implemented even with a fairly complicated circuit.

FIG. 4 shows another embodiment of the invention. In this example, circuit 15
, 16, 17, and 18 are selected on their power supply side and ground side, and switches 30A and 30B.

40A and 40B perform this selection function. For example, circuit 1
If it is desired to select 6, the gate signal C8I of the terminal 31A is used as a rubel to close the switch 30A, and the gate CG1 of the terminal 41A is also made a rubel to close the switch 40A and apply voltage to the circuit 15. In this state, circuit 15
It is possible to say that the only one is in an operating state and that an inspection has been performed. This embodiment has the advantage that when the scale of the circuit becomes large, the scale of the switch and control circuit can be reduced.

FIG. 5 shows still another embodiment of the present invention. In this embodiment, a circuit selection switch is not particularly provided, and the circuit is realized using some elements of an existing circuit to be tested. In the figure, the circuits 2A, 2B, ..., 2Z*MO8) Run raster 2A
A, 3A people, 28B, 3BB, ..., ..., 2ZZ
, 3ZZ. Such a circuit is a normal MO8
Often used inside ICs, MO8LSIs, etc. In the figure, MOS transistors 3AA, 38B, -, 3ZZ, etc. 1'! MO8 transistor 2AA, 28B,..., 2
It operates as a load such as ZZ and is usually called a load MOS transistor. This transistor is connected to the power supply side as shown by the dotted line in the figure, and in this case, the terminals 20A, 20B, ..., 202 connected to the power supply are connected to select signals (Gl, (corresponding to G2), perform the same inspection as before, and then connect it to the power supply side. This method eliminates the need to provide a new switch.

FIG. 6 shows yet another embodiment of the present invention T0 in this case circuits 36A, 36B1'! They are identical and connected in parallel on the circuit. The method of testing by closing either switch 35A or 35B is the same as before, but in this embodiment, based on the results of this test, if 36A or 36
The feature is that if either one of B is determined to be defective, the switch is always open and only non-defective products are used. For example, if 36A is determined to be normal and 36B is determined to be defective, the decoder circuit 9 is controlled and the output signal is set.
Fixed as Al''11 level, GB#'1O level,
From now on, only t'1t36A will be used.

This method is effective when there is redundancy in a circuit such as a gate array, and it is not necessarily necessary to connect two identical circuits in parallel. In other words, it has the advantage that the entire circuit can be configured using only normally operating circuits.

FIG. 7 shows yet another embodiment of the present invention. In this example, special measures have been taken to utilize circuits 2A and 2B, and in the previous examples, input signals for electrical operation were added to the circuits, but in this case, Add signals using light. The diodes 70A and 70B are used for light emission, and the luminous flux a emitted from the diodes 70A and 70B is applied to the circuits 2A and 2B through the darkness. Normal circuit 2A, 28μ transistor 61°6
Since active elements such as 2 are connected, a signal such as ``a'' can be applied to this junction from the outside. This method requires a special circuit for input signal application.
Since it does not need to be included in C, the circuit configuration becomes simple.

〔Effect of the invention〕

According to the present invention, the inside of a semiconductor electronic circuit can be inspected and diagnosed with a relatively simple circuit configuration, thereby increasing the reliability of semiconductor elements.
It also has great economic effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the principle of the semiconductor electronic circuit of the present invention, FIG. 2 is a circuit diagram of an embodiment of the semiconductor electronic circuit of the present invention, FIG. Figure 4, 5th
6 and 7 are circuit diagrams of other embodiments of the semiconductor electronic circuit of the present invention, respectively. l...voltage source, 2 people...circuit, 3 people...switch, 4...Fig.

Claims (1)

[Claims] 1. In semiconductor electronic circuits, the circuit is divided into several parts,
A part of the voltage source is operated by opening and closing a switch connected in series with the divided circuit in response to a signal from the control circuit, and the current flowing through the voltage source is detected by the detection circuit, and the waveform of the divided circuit is detected by the detection circuit. A semiconductor electronic circuit characterized in that it is configured to test, diagnose, and repair a circuit.