SU710045A1 - Logic circuit testing system - Google Patents

Description

one

The invention relates to instrumentation engineering, in particular, to a technique for monitoring and diagnosing logic circuits.

Industrial control measuring devices are known that allow one to measure the static and dynamic parameters of logic circuits 1. One of such devices contains level converters, a control unit, a write register, a decoder, a switching register, and is controlled from a mini-computer. Commands from the computer through level converters are sent to the unit, the controls that control the switching register and the exchange of information between the computer and the device. The data from the computer enters the record register and is written to the switching register via a decoder.

However, the monitoring device of this type is not adapted to diagnose faults in logic circuits due to mechanical switches, through which voltage is applied to logic circuits, which in turn prevents logical memory circuits from being diagnosed, and in addition, drastically reduces speed test

These deficiencies are eliminated in the specialized diagnostic control of diagnostic devices having electronic keys instead of mechanical ones.

The closest technical solution to the invention is a control system of logic circuits containing a controlling agent.

0 a machine whose output through signal level converters is connected to the first input of the first register and the input of the control unit connected by the first output through the second register to the input KOMj yTaTopa, and the second output to the first input of the reading unit and the second input of the first register 2, In this system The possibility of monitoring and diagnostics of logic circuits with faults causing an intermediate level of voltage at the output of the tested circuit between logic O and 1 is not provided. In the presence of such ners, the system with about 0.5 tnostyu not detect them sle.dovatelno, the results of monitoring and diagnosis obtained unreliable and inaccurate.

The purpose of the invention is to increase the reliability of control results.

This is achieved by the fact that the system additionally contains a decoder, an analysis unit and a comparators unit, the input of which is connected to the switch output, and the output to the second input of the readout unit connected to the input of the analysis unit, the output of which is converted via signals to transducers. computer, where the input of the decoder is connected to the output of the first register, and the output to one of the inputs of the second register and to the third input of the readout unit.

The drawing shows a block diagram of a system comprising signal level converters 1, a control unit 2, a register 3, a decoder 4, a read unit 5, a register 6, a switch 7, a comparators unit 8, an analysis unit 9, a computer (VM) 10 and a controlled logic circuit 11.

The system works as follows.

On a command, the contents of the VM 10 adder with the input output number and the logical value code supplied to this input are written to register 3. After the decoder 4, the logical value is written to the corresponding register bit 6, which through switch 7 is connected to circuit 11. When all the inputs of the circuit 1 1 served the desired input set, the command read from the VM. Then from the VM adder, register 3 records the number of the output from which information should be read into the VM. In turn, the block 8 through the switch 7 receives analog voltage values from all the outputs of the circuit 11. The decoder 4 passes through the block 5 a value only from that output, the number of which corresponds to the number written in register 3. From the output of block 5, the code of the output voltage - : the coupler enters the analysis unit 9, which through transducers 1 re00

gives in VM 10 code

II

or

01, corresponding to the value of the logical, W, O, h or intermediate voltage level at the readable output.

The presence of the comparators block 8 and the analysis block 9 makes it possible to increase the accuracy of control and diagnosis of circuits.

The processing of statistical data for monitoring and diagnosing malfunctions of large multichip integrated circuits showed that approximately 7% of them have faults caused by intermediate voltage at the output of the circuit. Therefore, when introducing the described system, the accuracy of control of integrated logic circuits is increased by 7%.

Claims (2)

Invention Formula A logic control system containing a control computer whose output is connected via signal level converters to the first input of the first register and the input of the control unit connected by the first output through the second register to the input of the switch, and the second output to the first input of the readout unit and the second input of the first register, characterized in that, in order to increase the reliability of the control result, the system further comprises a decoder, the analysis unit and the comparators unit, whose input is connected to the switch output, and the output to the second input of the readout unit connected to the input of the analysis unit, the output of which through the signal level converters is connected to the input of the control unit of the computer, and the decoder input is connected to the output of the first register, and the output - to one of the inputs of the second register and to the third input of the reading unit. Sources of information taken into account in the examination 1. Multipoint complex EleconS .D. Sat Electronic industry number 1, 1975. 2. Karasik V.M., Popov S.i., Katz M.F. Automatic control of constructive logical nodes. Sat Exchange of experience in electronics. Measurement and control № 3, 1973 (prototype).