JP2728718B2 - Semiconductor integrated circuit measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention measures various characteristics of a semiconductor integrated circuit for each item, and determines the quality of the semiconductor integrated circuit based on the measurement result. Related to the device.

(Prior Art) A semiconductor integrated circuit (IC) performs a final measurement before shipment to judge whether or not it is good, and ships only a good product. In particular, in a color television IC that handles video / chroma signals, it is determined whether or not output values are within specified ranges for various measurement items so that image quality does not deteriorate.
For this determination, a semiconductor integrated circuit measuring device called an IC tester is used.

FIG. 2 is a block diagram showing a configuration of a conventional IC tester for automatically determining a color television IC. The output signal S from the color TV IC 31 as a test IC is supplied to the IC tester 32 via a coaxial cable (not shown). Tester
In 32, the signal S consists of a matching resistor 33 and a buffer amplifier.
The signal is supplied to a signal processing circuit 36 via an input circuit 35 composed of 34.

In the signal processing circuit 36, a plurality of measurement circuits are provided corresponding to the measurement items of the IC 31. Reference numeral 37 denotes a DC measurement circuit, which is usually constituted by a low-pass filter, and measures the DC component of the signal S. 38 is a peak voltage measuring circuit, which is the peak voltage of the signal S or the peak-to-
It measures the voltage between peaks (peak to peak). Reference numeral 39 denotes a high-frequency measurement circuit, which comprises a video / chroma band detection circuit, and measures high-frequency components in this band. Numerals 40 and 41 are phase voltage measuring circuits each composed of a multiplier. The one phase voltage measuring circuit 40 is supplied with a square wave signal serving as a reference for the phase generated by the phase reference signal generator 42. The other phase voltage measuring circuit 41 is supplied with the square wave signal from the phase reference signal generator 42 via the phase shift circuit 43.
Is supplied with a square wave signal whose phase is shifted by 90 °. The one phase voltage measuring circuit 40 outputs a cosine signal component, and the other phase voltage measuring circuit 41 outputs a sine signal component.

A DC measurement circuit 37 provided in the signal processing circuit 36,
The outputs of the peak voltage measuring circuit 38, the high frequency measuring circuit 39, and the phase voltage measuring circuits 40 and 41 are supplied to an analog / digital converter (A / D converter) 45 via a measurement item switching circuit 44 composed of a semiconductor relay or the like. Selectively supplied to The signal selected by the measurement item switching circuit 44 is converted into a digital signal by the A / D converter 45 and taken into the control circuit 46 as data. The control circuit 46 determines, based on the acquired data, whether or not the value of the measurement item falls within a specified range by calculation. A timing generator 47 sets a measurement point of the output signal S of the IC 31, and sets a conversion timing in the A / D converter 45.

By the way, the measurement with the above-mentioned conventional IC tester has the following problems. First, measurement items of different items cannot be measured at the same time due to the switching by the measurement item switching circuit 44. That is, the relationship between the measurement items cannot be measured for the same input. For example, since the relationship between the phase and the DC component is determined based on the value at the same time, a determination result having no meaning is obtained unless both items are measured at the same time. Further, since there is no storage means for the measurement data, there is also a problem that the fluctuation of the measurement data with time cannot be read.

Recently, for color televisions that handle video / chroma signals
In ICs, measurement from horizontal units to screen units has become necessary due to the complexity of the internal configuration accompanying functional improvements. When measuring on a screen-by-screen basis with the above-mentioned conventional IC tester,
Each measurement point in one frame of scanning is set by the timing generator 47, and the same measurement point is measured for each item. Therefore, the quality of the same measurement point repeated every 1/30 second is determined for each measurement item. Therefore, if there are many types of measurement items in the screen unit, the test time becomes extremely long.

(Problems to be Solved by the Invention) As described above, in the related art, each measurement inspection item is selected by the switching circuit, and AD conversion and arithmetic processing are performed each time, so that simultaneous measurement of a plurality of parameters cannot be performed. . In addition, there is a drawback that various measurements cannot be performed due to temporal variations.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor integrated circuit measurement device that can simultaneously measure different items and determine the quality of measurement data on a screen at a high speed. To provide.

[Structure of the Invention] (Means for Solving the Problems) This semiconductor integrated circuit measuring apparatus comprises: a plurality of measuring means provided corresponding to measurement items of a semiconductor integrated circuit to be measured;
A plurality of analog-to-digital conversion means provided for each of the plurality of measurement means for converting the output of each measurement means from analog to digital; a data storage means for storing outputs of the plurality of analog-to-digital conversion means; An address selector for designating an address to the data storage means, at least, the analog-to-digital conversion of each of the plurality of measurement means at the same time, and storing the respective measurement data at the same time in the data storage means in parallel; The analog-digital conversion means, so that each measurement data is stored and the address to the data storage means is updated.
A timing generation circuit for sending a control signal to each of the data storage means and the address selector; a data selector capable of designating each measurement data stored in the data storage means in accordance with the measurement item; By specifying a determination point of the measurement data stored in the storage means and specifying a measurement item by the data selector, predetermined measurement data is read from the data storage means, and the semiconductor integrated circuit to be measured is read out. Determining means for determining a measurement result according to each measurement item.

(Operation) In each measurement item, a designated measurement point is measured at the same time. The measurement results are sequentially written to the assigned memories. Based on the contents of this memory, pass / fail judgment based on the mutual relationship between the measurement results and pass / fail judgment with respect to temporal fluctuations are performed, and pass / fail judgment of the measurement results for each screen is performed at high speed.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a semiconductor integrated circuit measuring device according to the present invention. An output signal S from a test IC, for example, a color television IC, is supplied to the IC tester 2 via a coaxial cable (not shown). In the tester 2, the signal S is supplied to a signal processing circuit 6 via an input circuit 5 including a matching resistor 3 and a buffer amplifier 4.

The signal processing circuit 6 includes a DC measurement circuit 7 composed of a low-pass filter for measuring a DC component of the signal S, a peak voltage of the signal S, or a peak-to-peak signal, as in the conventional case. And a high-frequency measuring circuit 9 for measuring high-frequency components in the video / chroma band. Further, in the same manner as in the related art, in the phase voltage measuring circuits 10 and 11 including multipliers, a phase reference signal generator 12 supplies a square wave signal serving as a phase reference. Here, since the square wave signal from the phase reference signal generator 12 is supplied to the phase voltage measurement circuit 11 via the phase shift circuit 13, the phase of the square wave supplied to the phase voltage measurement circuit 10 is A 90 ° shifted square wave is provided. One phase voltage measuring circuit 10 outputs a cosine signal component, and the other phase voltage measuring circuit 11 outputs a sine signal component, with each of the reference square waves having a phase of zero degree.

The outputs of the signal processing circuits 6 corresponding to the respective measurement items are supplied to analog / digital converters (A / D converters) indicated by 14 to 18 and are converted from analog signals to digital signals. The output of each A / D converter 14-18 is RAM (rand
om access memory) is sequentially written to the storage device 19. That is, the timing generation circuit 20 outputs the strobe signal T1 to the A / D converters 14 to 18 at the same timing, and outputs the write signal T2 to the storage device 19 at the same time. As a result, the outputs of the respective measurement circuits in the signal processing circuit 6 are A / D converted at the same time, and the measurement data at the same time is stored in the storage device 19 in parallel. T3 is an address signal to the storage device 19, and is incremented each time measurement data is written via the address selector 21. Thus, the signals T1, T2, T3
Are linked, and the measurement data is stored in the storage device 19.

The output of the storage device 19 is input to a control circuit 23 including an arithmetic processing device via a data selector 22, where arithmetic processing, data comparison, and the like are performed according to the measurement items. That is, the address select signal AS is supplied from the control circuit 23 to the address selector 21, and the determination point of the measurement data in the storage device 19 is designated. Further, the data select signal is sent from the control circuit 23 to the data selector.
DS is supplied, and one of the measurement items in the signal processing circuit 6 is designated.

According to the above configuration, measurement at the same time can be performed for multiple items, and measurement data at different times are stored for each item, and various pass / fail judgments are quickly performed by the control circuit 23. Therefore, for video / chroma signals of a color television IC, higher-speed and more reliable measurement can be realized in units of screens as compared with the related art.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a semiconductor integrated circuit measuring apparatus which can simultaneously measure different items and can judge the quality of measurement data of each screen at a high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a conventional IC tester for measuring and inspecting a video / chroma signal of a color television IC. 1 ... color TV IC, 2 ... IC tester, 3 ... matching resistor, 4 ... buffer amplifier, 5 ... input circuit,
6 ... signal processing circuit, 7 ... DC voltage measurement circuit, 8 ...
Peak voltage measurement circuit, 9 ... High frequency voltage measurement circuit, 10, 1
1 ... Phase voltage measurement circuit, 12 ... Phase reference signal generator, 1
3… Phase shift circuit, 14,15,16,17,18 …… A / D converter,
19: storage device, 20: timing generator, 21: address selector, 22: data selector, 23: control circuit.

Claims (2)

(57) [Claims] 1. A plurality of measuring means provided corresponding to a measurement item of a semiconductor integrated circuit to be measured, and a plurality of measuring means provided for each of the plurality of measuring means for converting an output of each measuring means from analog to digital. Analog-to-digital conversion means; data storage means for storing outputs of the plurality of analog-to-digital conversion means; an address selector for designating an address to the data storage means; The analog / digital conversion is performed so that each measurement data at the same time is stored in parallel in the data storage means, and each measurement data is stored and the address to the data storage means is updated. A timing generation circuit for sending a control signal to each of the digital conversion means, the data storage means and the address selector; A data selector capable of designating each measurement data stored in the data storage means in accordance with the measurement item, and a determination point of the measurement data stored in the data storage means being specified by the address selector; A predetermined measurement data is read from the data storage means when a measurement item is designated by the data selector, and a determination means for determining a measurement result corresponding to each measurement item of the semiconductor integrated circuit to be measured is provided. A semiconductor integrated circuit measuring device characterized by the above-mentioned. 2. The semiconductor integrated circuit to be measured is an IC for a color television, and the measurement items are provided in a type required for measurement of a television screen unit.
The semiconductor integrated circuit measuring device according to the above.