SU1654823A1 - Device for testing digital units - Google Patents

Abstract

The invention relates to automation and computing and can be used in automated systems for testing integrated circuits. The purpose of the invention is to expand the field of application of the device. The device contains a measuring node 8, contacts 30-35 and winding 36-41 relay groups, current-limiting elements made on resistors 9,10, load element made on resistor 19, pulse shaper 20, comparator 21, registers 24, 25, decoders - 28.29, a group of formers 13-18 pulses. Before the circuit is monitored, the probes are contacted with the circuit contacts by sequentially feeding signals from the power supply buses 11,12 to the earth contact and the power supply contact of the monitored circuit and then feeding signals from the circuit contacts through the relay contacts to the comparator 21 input. 23 device failure will be a single signal. 1il G (L

Description

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The invention relates to automation and computing and can be used in automated systems for testing integrated circuits.

The purpose of the invention is to expand the field of application of the device.

The drawing is given a functional diagram of the device.

The device contains a monitored block 1, outputs 2 and 3 of the device for connecting to the power input and the zero potential input of the monitored block, respectively, a group of information-f5 ing inputs-outputs 4-7 of the device for connecting to the inputs-outputs of the monitored block, measuring node 8, current-limiting elements made on resistors 9 and 10, buses 11 and 12 of the device power supply, hinge jiy pulse shaper 13-18, load element made on resistor 19, pulse shaper 20, comparator 21, reference potential input 22 la device exit

23 device malfunctions, registers

24 and 25, informational inputs 26 and 27 of the device, decoders 28 and 29, a group of switches made on a relay group with contacts 30-35 and windings 36-41.

The formers 13-18 of the group are amplifiers that match the outputs of the decoder 28 and 29 with the control windings of the 36-41 relay groups.

Chips, cells, etc. can be used as a monitored unit.

The device works as follows.

Initially, the terminals of the measuring unit 8 are switched to the off state (the corresponding control circuit is not shown).

After the block under study (for example, a microcircuit) is inserted under the probes and the coordinate table is lifted to provide contacts with the sites of the monitored block 1, a register is written to the register 24 that activates the first output of the decoder 28, which, through the group 13 pulse generator, turns on the relay coil 36 groups. As a result, the voltage c. Bus 12 devices through a resistor 10 and the contacts 31 of the relay group is fed to the contact pad of the zero potential of the monitored unit. Then on

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Register 25 receives a sequence of codes, which with the help of decoder 29 alternately closes the contacts 32-35 of the relay group. After each of the contacts 32-35 of the relay group is closed, if there are contacts of the inputs-outputs of the device groups 4-7 with the platform of the monitored block through the resistor 10, contact 31 of the relay group, one of the contacts 32-35 of the relay group and resistor 19 is flowing current. As a result, the voltage at the output of the pulse driver 20 exceeds the reference voltage at the device input 22, and a logical signal 1 is generated at the device output 23.

The absence of current through the resistor 19 results in the appearance at the output 23 of a device malfunction of a logic O signal.

In practice, the absence of current through the resistor 19 is possible either in the absence of contact with the platform of the monitored unit, or in the presence of a large (hundreds of kOhm) resistance between the housing and the corresponding output of the monitored unit.

For integrated circuits of various series, the resistance value between the power supply circuits and the output of the unit is significantly less than the resistance between the case and the output of the unit. Therefore, after receiving a zero signal at the output 23 of the device when the contact 31 of the relay group 31 is closed, it is necessary to send a code to the input of the register 24, the closing contact 30 of the relay group, thereby applying voltage from the device bus 11 to the power input of the monitored unit. If in this case a zero signal appears at the output 23 of the device, this means the absence of contact with the corresponding contact pad of the corresponding controlled unit. The code recorded in register 25 indicates the number of this pad.

Claims (1)

If there is contact with all the pads of the controlled chip, the registers 24 and 25 record codes disconnecting all contacts 30-35 of the relay group, and begins checking the controlled chip with the aid of measuring unit 8. Inventive formula thirty 35 40 45 50 55 A device for controlling digital blocks, containing a switchboard group A device for controlling digital blocks, containing a group of switches, a measuring node and two current-limiting elements made on the first and second resistors, the first power supply bus of the device being connected to the first information input-output of the first switch through the first resistor the group, the second information input-output of which is connected to the first information output of the device for connection to the power input of the monitored unit, differing Moreover, in order to expand the field of application of the device, a load element made on the third resistor, a pulse shaper, a comparator, two registers, two decoders and a group of shapers, are entered into it, and the information inputs of the first and second registers form the first and the second information inputs of the device, the outputs of the first and second registers are connected to the information inputs of the first and second decoders, respectively, the outputs of the first and second decoders through sponds conditioners pulse group are connected to the control inputs of the respective switches of the group, the second information output of the device for connecting the zero potential input to the input (The monitored block is connected to the first information input / output of the second switch of the group, the second information input-output of which is connected via the second resistor to the second power supply bus of the device the connections to the inputs-outputs of the controlled unit are connected to the first information inputs-outputs of the corresponding switches of the group, the second information inputs-you the strokes of which are connected to the input of the pulse generator and through the third resistor are connected to the zero potential bus of the device, the output of the pulse former is connected to the first information input of the comparator, the second information input of which is the input of the reference potential of the device, the output of the comparator is the output of the device failure, the first and the second outputs of the device and the group of information inputs and outputs of the device are connected to the corresponding inputs of the measuring node.