Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – With rotor
Patent
1991-02-28
1992-07-14
Karlsen, Ernest F.
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
With rotor
371 226, G01R 3128
Patent
active
051306484
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an instrument for checking the operational state of integrated circuits, so-called IC-circuits.
When testing an electronic board or card for faults, one problem encountered is the difficulty in pointing to a specific faulty, non-functioning IC-circuit. It is seldom that a given faulty IC-circuit can be indicated with the aid of known equipment. Normally, it is only possible to point to a group of components which contain a faulty IC-circuit, such as a whole electronic board for instance.
In the case of electronic boards which include a microprocessor, equipment is found which will stimulate the microprocessor. This involves substituting the microprocessor for a processor which will behave in the same manner as the microprocessor and which will emit pulses on the board similar to those emitted by the microprocessor. Such pulses stimulate the IC-circuits on the board and give rise to so-called signatures, i.e. output signals on the various board inputs and outputs, these output signals either being static or comprising sequences of output signals. Since the appearance of the signatures generated on a fault-free board is known, the signatures are compared with said pulses, so as to establish whether or not the board is faulty, and if so where the fault lies.
However, when establishing that a board is faulty, it remains to isolate the faulty IC-circuit. In the case of data buses and address buses, for instance, it is not unusual for about 10-20 IC-circuits to influence a given signature.
Furthermore, when an external processor is connected to the board, it is necessary to disengage the board from its normal conductive state.
A further problem arises when an electronic board is not fitted with a microprocessor. In this case, the IC-circuits can be stimulated, for instance, through a so-called short-edge contact. It is highly improbable, however, in this case that the faulty IC-circuit will be located within a reasonable time period.
Consequently, there is a great need, and also a great desire, for an instrument by means of which a faulty IC-circuit can be detected from a plurality of IC-circuits on an electronic board.
It is also desirable that detection of a faulty IC-circuit can be effected without disconnecting the board, i.e. that said detection can be effected while the board conducts current.
Such an instrument would, inter alia, render it unnecessary to scrap the whole of the board, and therewith enable the board to be repaired, by simply replacing the faulty IC-circuit.
The present invention provides such an instrument by means of which IC-circuit by IC-circuit can be checked and which will enable the check to be made while voltage is applied to the board in a normal manner.
The invention results in significant savings in costs, partly because the time taken to establish a fault is greatly reduced, and partly because a faulty card can be repaired instead of being scrapped.
The present invention thus relates to an instrument for checking the operational state of IC-circuits, and particularly for checking the operational state of current-conducting IC-circuits located on electronic boards or cards, said instrument including an electronic circuit which is operative to control and evaluate the signal to and from the pins of the IC-circuit, and which further includes a so-called test-clip which is connected to the electronic circuit and which is intended to be connected to the pins of an IC-circuit, said instrument being characterized in that the electronic circuit includes a microprocessor which is programmed with logic functions intended for one or more IC-circuits and which includes a sequence logic circuit operative to control electronic switches which via the test-clip can be connected to the pins of the IC-circuit, in a sequence which is predetermined for each IC-circuit, said switches being operative to apply to the respective inputs of the IC-circuit a short pulse of high current strength, said pulse having a sufficiently high current strength for the input concerned
REFERENCES:
patent: 3870953 (1975-03-01), Boatman et al.
patent: 4132946 (1979-01-01), Holdren et al.
patent: 4439858 (1984-03-01), Petersen
patent: 4484329 (1984-11-01), Slamka et al.
patent: 4583223 (1986-04-01), Inoue et al.
patent: 4588945 (1986-05-01), Groves et al.
patent: 4654850 (1987-03-01), Rodrigues
patent: 4827208 (1989-05-01), Oliver et al.
Modern Elektronik, vol. 17, 1983, Rick Robinson "In-Circuit Test Kortar Liuslangen?", pp. 35-38.
LandOfFree
Instrument for checking the operational state of an IC-circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Instrument for checking the operational state of an IC-circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Instrument for checking the operational state of an IC-circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-337395