JPS6134481A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To enable the implementation of an effective continuity test without use of any costly equipment, by making an internal integrated circuit operate by itself diregarding the state of an input signal from outside only while a oscillation circuit operation signal is applied to a three-value input circuit. CONSTITUTION:In the continuity test, as a DC voltage for operation in applied to an input terminal of a three-value circuit 4, an operation permit signal is provided to a spontaneous oscillation circuit 5 and an operation control circuit 6 from the circuit 4. In this case, the operation voltage value of the three-value input circuit is normally set for than almost doubling the service voltage value. The circuit 6 generates an input switching signal to the input circuit 1 which is controlled only to a signal generated by the circuit 6. Thereafter, the IC stays in operation continually by an operation control signal of a main function section 2 and an output circuit 3 as generated from the circuit 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a semiconductor integrated circuit device, and particularly relates to a device suitable for an electrical conduction test.

(Prior Art) Semiconductor integrated circuit devices' (hereinafter referred to as I and C) are subjected to a current conduction test in a high temperature atmosphere prior to normal use in order to prevent failures during initial use.

Current testing can be roughly divided into the following two methods depending on the form of voltage application.

Method 1゜ Tested 1. Apply a predetermined voltage to the power supply terminal of C.

A method in which DC voltage is applied to the input/output terminals through a resistor, etc. This is hereinafter referred to as the static bias method.

Method 2゜ Apply a predetermined voltage to the power supply terminals of I and C0 under test.

The input terminal has 1. C, t - Method of applying control signals for operation. This is hereinafter referred to as the dynamic bias method.

The static bias method is meta because the test equipment and jig type 1 are cheap. Although it has the advantage of low test cost, the test subject 1.
The disadvantage is that the effect of a single energization test is not sufficient because C does not perform a switching operation. - 10,000, the dynamic bias method can be used to
．． It is very effective as a conduction test because it can operate all internal circuit elements of C, but on the other hand, it is a testing device and
As a result, 1. The drawback is that the cost of conducting the current test of C. is high.

(Objective of the Invention) The purpose of the present invention is to provide I, C, and the like that can be expected to be sufficiently effective in one energization test while minimizing the increase in the cost of the energization test (Example) Next, the present invention I will explain it using an example meeting drawing.

1st is the conventional 1. It is a functional block diagram of C.

When conducting a current conduction test using the dynamic bias method described above for the conventional I, C shown in FIG. 1, the input circuit 1. Main function section 2. Output circuit 3 operates. However, a large number of 1. When testing 1.C, the test target 1.C. Since C performs a switching operation, it is important to take measures to prevent malfunctions caused by switching noise or significant changes in instantaneous current. Further, the number of control signals usually requires the same number of types as the number of input terminals of I, C, and the like to be tested, and therefore the energization test apparatus becomes complicated and large, and the test cost increases.

FIG. 2 is a functional block diagram of I and C according to an embodiment of the present invention. In the same figure, input circuit 1゜main function section 2
．． The output circuit 3 is the conventional 1. It has the same function as C, but
The three-value input circuit 4, the free-running oscillation circuit 5 controlled by the output signal of the three-value input circuit 4, and the operation signals of the I, C, and the like? The operation control circuit 6 that generates the data is newly provided on the same chip. To the input terminal connected to the three-value input circuit 4 during the energization test.

When a DC voltage for operating the three-value input circuit is applied, an operation permission signal is applied from the three-value input circuit 4 to the free-running oscillation circuit 5 and the operation control circuit 1. In this case, the three-value input circuit operating voltage value is set to a value approximately twice the normally used voltage value. , the input circuit 1 is controlled only by the signal generated by the operation control circuit 6.

Thereafter, the skeletons I, C continue to operate according to the operation control signals of the main function section 2 and the output circuit 3 generated by the operation control circuit 6.

Therefore, in the energization test of I, C' according to this embodiment, in addition to the ground wire, only the power supply voltage input g line and the three-value input circuit operation line 281[class] were tested. As a result, it is possible to perform highly effective current testing even though the current testing equipment and jigs are inexpensive. f7'c Three-value input image of this example w
Since r cannot operate with the voltage applied during normal use, the normal operation is the conventional 1. There is no difference from C.

(Description of Effects) As described above, according to the present invention, it is possible to provide a semiconductor integrated circuit device that can carry out effective energization tests without using expensive equipment.

[Brief explanation of the drawing]

Figure 1 is a functional block diagram of a conventional semiconductor integrated circuit device.
FIG. 2 is a functional block diagram of a semiconductor integrated circuit device according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Input circuit, 2... Main function part, 3... Output circuit, 4... Three-value input circuit, 5... Free-running oscillation circuit, 6
...Operation control circuit

Claims (1)

[Claims] The semiconductor integrated circuit device includes a three-value input circuit, an oscillation circuit controlled by the output signal of the three-value input circuit, and an operation control circuit that generates an operation signal for the internal integrated circuit,
Only during the period when the oscillation circuit operation signal is applied to the three-value input circuit, the internal integrated circuit operates by itself regardless of the state of the external input signal, and the oscillation circuit operation signal is applied to the three-value input circuit. 2. A semiconductor integrated circuit device, wherein the semiconductor integrated circuit device operates according to control of the input signal from the outside when the input signal is not input.