JPH03282381A - Integrated circuit device - Google Patents

Abstract

PURPOSE:To effectively perform a thermal acceleration test without reducing economy by generating a test control signal inside an integrated circuit (IC) device and simultaneously outputting it to the outside terminal. CONSTITUTION:When a test signal 13 is inactive, an input signal 7 is inputted to a control circuit 5 by a selection in an input changeover circuit 6. The control signals 8, 9 are outputted to each part of the IC device 1 inside by the circuit 5 in accordance with this signal 7, and a signal 10 is outputted from an output signal generator 2 and transmitted to the output terminal through an output changeover circuit 3, then the device 1 performs the normal operation. Next, when the signal 13 is active, a control signal 11 generated from a test control signal generating circuit 4 is outputted as an output signal 12 through the circuit 3 and also inputted to the circuit 5 through the circuit 6, then the signals 8, 9 are outputted by the circuit 5. In the circuit 4, the next signal 11 is generated by the signal 9, and the same operations are repeated thereafter. Then, by observing these signals from the outside, the decision is made whether the device 1 is properly operated during the thermal acceleration test for the device 1, or not.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to integrated circuit devices.

[Prior Art] Conventionally, a thermally accelerated test of an integrated circuit device has been carried out by heating the integrated circuit device while applying a voltage to the power supply terminal thereof. At this time, the input terminal of the integrated circuit device was fixed at a power supply potential or a ground potential.

[Problems to be Solved by the Invention] The conventional thermally accelerated testing method described above has the following drawbacks.

(1) Since the input terminal is fixed and the inside of the integrated circuit device hardly operates, the current flowing through the internal elements differs from the actual operating state, reducing the effectiveness of the accelerated test.

(2) Furthermore, in order to perform an accelerated test while the internal parts are in operation, expensive equipment such as a pattern generator is required, which is economically disadvantageous.

(3) Furthermore, even when a pattern generator is used, it is quite difficult to realize this because it is necessary to monitor whether the integrated circuit device is operating correctly.

SUMMARY OF THE INVENTION An object of the present invention is to provide an integrated circuit device in which a thermally accelerated test can be performed while the device is in operation, without requiring expensive equipment such as a pattern generator.

[Means for Solving the Problems] An integrated circuit device of the present invention includes: a test control signal generation circuit that generates a test control signal when an external test signal is active; and an integrated circuit that generates a test control signal when the test signal is inactive. an output switching circuit that outputs an output signal based on the normal operation of the device to an output terminal, and a test control signal output from the test control signal generation circuit when the test signal is active; Input switching that outputs the input signal input to the integrated circuit device and the test control signal output from the output switching circuit when the test signal is active to the control circuit that controls the operation of the entire integrated circuit device. The test control signal generating circuit is configured to generate a test control signal based on the output signal of the control circuit.

[Function] When the test signal is at active level, it becomes a test mode, and a test control signal is generated and output to the outside of the integrated circuit device, and is also input to the control circuit to generate the next test control signal.

Therefore, by observing this test control signal, the thermally accelerated test can be performed effectively and economically.

[Embodiments] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an integrated circuit device according to an embodiment of the present invention.

This integrated circuit device 1 includes an output signal generator 2 (for example, a memory), an output switching circuit 3, a test control signal generation circuit 4, a control circuit 5 (for example, a CPU), an input switching circuit 6,
It is composed of other circuits not shown.

The output signal generator 2 generates a control signal 8 (command) of the control circuit 5.
outputs signal 10. Test control signal generation circuit 4
generates a test control signal 11 based on the control signal 9 of the control circuit 5 when the test signal 13 is active.

The output switching circuit 3 and the input switching circuit 6 select the output signal 10 and input signal 7 of the output signal generator 2, respectively, when the test signal 3 is inactive, and select the test control signal 11, and the output signal, respectively, when the test signal 3 is active. The output signal 12 (test control signal) of the switching circuit 3 is selected and outputted to an output terminal (not shown) and the control circuit 5, respectively.

Next, the operation of this embodiment will be explained.

(1) When the test signal 13 is inactive, in this case, the input switching circuit 6 selects the input signal 7, and the control circuit 5
Output to. The control circuit 5 outputs output signals 8, 9, etc. to each part in the integrated circuit device 1 in response to the input signal 7. An output signal 8 is outputted to the output signal generator 2, and a signal lO is outputted from the output signal generator 2 in accordance with the output signal 8, and is outputted to the output terminal via the output switching circuit 3. in this way,
When test signal 3 is inactive, this integrated circuit device 1
performs normal operation.

(2) When the test signal 3 is active In this case, the test control signal generation circuit 4 generates the test control signal 11, which is output as the output signal 12 to the external terminal via the output switching circuit 3, and the input switching circuit 6 and is input to the control circuit 5. Control circuit 5 receives test control signal 1
1 outputs various control signals 8, 9, etc. The test control signal generation circuit 4 generates the next test control signal 11 based on the control signal 9, and the same operation is repeated thereafter. By observing this test control signal 11 from the outside, it is possible to detect the present integrated circuit device 1 during a thermal acceleration test of the present integrated circuit device 1! You can determine whether or not it is working correctly.

Note that the integrated circuit test circuit (test control signal generation circuit 4
), it can be easily realized by simply adding switching circuits 3 and 6.

FIG. 2 is a block diagram showing an example of application of the present invention.

In this application example, n integrated circuit devices 21, 22, . A comparator 24 which compares these and sets the output to "0" and causes a monitoring light emitting diode 25 to emit light if a monarchy occurs.
has been implemented.

This application example has the advantage that the operating states of a plurality of integrated circuit devices can be easily monitored. In addition, since low-integration integrated circuits such as comparators are generally highly reliable and can be used repeatedly, economical efficiency is not reduced.

[Effects of the Invention] As explained above, the present invention improves the effectiveness of thermally accelerated testing without reducing economic efficiency by generating a test control signal inside an integrated circuit device and simultaneously outputting it to an external terminal. It has the effect of making

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an integrated circuit device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing an application example of the present invention. DESCRIPTION OF SYMBOLS 1... Integrated circuit device, 2... Output signal generator, 3... Output switching circuit, 4... Test control signal generation circuit, 5... Control circuit, 6... Input switching circuit, 7... Input signal, 8.9... Control signal, 10... Output signal, 11... Test control signal, 12... Output signal, 21-2n... Integrated circuit device, 24. ... Comparator 25 ... Monitoring light emitting diode, 26 ... Board

Claims (1)

[Claims] 1. In an integrated circuit device, a test control signal generation circuit that generates a test control signal when an external test signal is active; and a normal operation of the integrated circuit device when the test signal is inactive. an output switching circuit that outputs a test control signal output from the test control signal generation circuit to an output terminal when the test signal is active; an input switching circuit that outputs an input signal input to the integrated circuit device and a test control signal output from the output switching circuit when the test signal is active to a control circuit that controls the operation of the entire integrated circuit device. An integrated circuit device, wherein the test control signal generation circuit generates a test control signal based on an output signal of the control circuit.