Method of and device for testing multiple power supply connections of an integrated circuit on a printed circuit board

Claim 2

An integrated circuit chip comprising: multiple power supply connections for at least two different supply voltages with at least two separate ones of said power supply connections carrying the same rated supply voltage, an on-chip test comparison circuit having input terminals coupled to respective test leads, a selection mechanism coupled between the supply connections and the test comparison circuit via said respective test leads in order to selectively and sequentially connect only power supply connections associated with the same supply voltage to respective input terminals of the test comparison circuit thereby to produce, in a test state of the integrated circuit an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value.

Claim 3

An integrated circuit as claimed in claim 1 wherein said selection mechanism comprises a commutation mechanism for inverting the selection of two power supply connections for input terminals of the test comparison circuit.

Claim 4

An integrated circuit chip comprising: at least two separate power supply connections which carry the same rated supply voltage, means connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and a data flip-flop which is fed by the output of the test comparison circuit in order to output a result bit for external evaluation by including the flip-flop in a serial shift register.

Claim 5

An integrated circuit chip comprising: at least two separate power supply connections which carry the same rated supply voltage, means connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and a data flip-flop which is fed by the output of the test comparison circuit in order to output a result bit for external evaluation by including the flip-flop in a serial shift register.

Claim 6

An integrated circuit as claimed in claim 3 further comprising a second data flip-flop for the storage of a control bit for selecting said test leads and for receiving, by including the second data flip-flop in a serial shift register, a control bit from an external control device.

Claim 9

An electronic apparatus comprising: a printed circuit board including at least first and second separate power supply connection elements each of which carries the same rated supply voltage whereby a standard voltage appears between said first and second power supply connection elements when said elements function correctly, a conductive track on said printed circuit board between and connected to said first and second power supply connection elements, an integrated circuit chip mounted on said printed circuit board such that said power supply connection elements provide power supply connections for circuit elements of said integrated circuit chip, said integrated circuit chip further comprising; a test comparison circuit having first and second input terminals and an output, first and second test leads connecting said first and second input terminals of the test comparison circuit to said first and second power supply connections, respectively, said test comparison circuit being responsive, in a test state of the integrated circuit, to a critical deviation of the voltage appearing between said first and second power supply connection elements from said standard voltage for producing an error signal at said output of the test comparison circuit and which is indicative of a malfunction in a power supply connection element.

Claim 10

An electronic apparatus comprising: a printed circuit board including at least first and second separate power supply connection elements each of which carries the same rated supply voltage whereby a standard voltage appears between said first and second power supply connection elements when said elements function correctly, a conductive track on said printed circuit board between and connected to said first and second power supply connection elements, an integrated circuit chip mounted on said printed circuit board such that said power supply connection elements provide power supply connections for circuit elements of said integrated circuit chip, said integrated circuit chip further comprising; a test comparison circuit having first and second input terminals and an output, first and second test leads connecting said first and second input terminals of the test comparison circuit to said first and second power supply connections, respectively, said test comparison circuit being responsive, in a test state of the integrated circuit, to a critical deviation of the voltage appearing between said first and second power supply connection elements from said standard voltage for producing an error signal at said output of the test comparison circuit and which is indicative of a malfunction in a power supply connection element.

Claim 11

An electronic apparatus as claimed in claim 6, comprising at least said first and second power supply connection elements and a third power supply connection element each of which elements carries said same rated supply voltage, and a selection mechanism on said integrated circuit chip and coupled to said power supply connection elements and to said input terminals of the test comparison circuit for selectively connecting two of said power supply connection elements at a time to respective ones of said first and second input terminals of the test comparison circuit.

Claim 12

An electronic apparatus as claimed in claim 6, wherein said test comparison circuit has a threshold voltage level related to said critical voltage deviation.

Claim 13

An electronic apparatus as claimed in claim 6, wherien said power supply connection elements extend into said integrated circuit chip, said integrated circuit chip further comprising a conductive track coupled between said power supply connection elements.

Claim 14

An electronic apparatus as claimed in claim 6 further comprising at least third and fourth power supply connection elements each of which carries a same second rated supply voltage, and means for selectively connecting either said first and second power supply connection elements or said third and fourth power supply connection elements to said first and second input terminals, respectively, of the test comparison circuit during said test state.

Claim 17

An electronic apparatus comprising: a printed circuit board including at least first and second separate power supply connection pins, each of which carries the same rated supply voltage, an integrated circuit chip mounted on said printed circuit board and comprising an on-chip test comparison circuit, first and second bi-directional test leads, at least first and second physically separate bidirectional power supply connection elements connected via said first and second bidirectional test leads to respective first and second input terminals of the test comparison circuit and further connected to said first and second power supply connection pins, respectively, such that only bidirectional current paths are present between said first and second power supply connection pins and said first and second input terminals whereby said power supply connection elements each carry said same rated supply voltage and, in a test state, an error signal is produced at a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connection elements exceeds a critical value.

Claim 18

An electronic apparatus comprising: a printed circuit board including at least first and second separate power supply connection pins, each of which carries the same rated supply voltage, an integrated circuit chip mounted on said printed circuit board and comprising an on-chip test comparison circuit, first and second bi-directional test leads, at least first and second physically separate bidirectional power supply connection elements connected via said first and second bidirectional test leads to respective first and second input terminals of the test comparison circuit and further connected to said first and second power supply connection pins, respectively, such that only bidirectional current paths are present between said first and second power supply connection pins and said first and second input terminals whereby said power supply connection elements each carry said same rated supply voltage and, in a test state, an error signal is produced at a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connection elements exceeds a critical value.

Claim 19

An integrated circuit chip comprising: at least three separate power supply connections which carry the same rated supply voltage, means including a selection mechanism for connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and wherein the selection mechanism is connected between the power supply connections and the test comparison circuit in order to selectively connect only two of said power supply connections at a time to respective input terminals of the test comparison circuit.

Claim 20

An integrated circuit chip comprising: at least three separate power supply connections which carry the same rated supply voltage, means including a selection mechanism for connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and wherein the selection mechanism is connected between the power supply connections and the test comparison circuit in order to selectively connect only two of said power supply connections at a time to respective input terminals of the test comparison circuit.

Claim 21

An integrated circuit as claimed in claim 13 comprising multiple power supply connections for at least two different supply voltages, a further selection mechanism coupled between the supply connections and the test comparison circuit in order to selectively connect in sequence only power supply connections associated with the same supply voltage to respective input terminals of the test comparison circuit.

Claim 22

An integrated circuit as claimed in claim 14 wherein at least one selection mechanism comprises a commutation mechanism for inverting the selection of two power supply connections for input terminals of the test comparison circuit.

Claim 23

An integrated circuit as claimed in claim 13 wherein the test comparison circuit comprises a discriminator circuit for detecting said critical deviation and an output circuit which is fed thereby in order to form a standard binary representation of the error signal.

Claim 24

An integrated circuit as claimed in claim 13 further comprising a data flip-flop which is fed by an output of the test comparison circuit in order to output a result bit for external evaluation by including the flip-flop in a serial shift register.

Claim 25

An integrated circuit as claimed in claim 17 further comprising a second data flip-flop for the storage of a control bit for selecting said test leads and for receiving, by including the second data flip-flop in a serial shift register, a control bit from an external control device.

Claim 26

An integrated circuit as claimed in claim 18, further comprising a third data flip-flop for storing a second control bit for the selective activation of any power supply connection and for receiving, by including the third data flip-flop in a serial shift register, a further control bit from the external control device.

Claim 27

An integrated circuit as claimed in claim 13, comprising: multiple power supply connections for at least two different supply voltages, a further selection mechanism coupled between the supply connections and the test comparison circuit in order to selectively connect each time only power supply connections associated with the same supply voltage to respective input terminals of the test comparison circuit.

Claim 28

An integrated circuit chip comprising: at least two separate power supply connections which carry the same rated supply voltage, means connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and wherein said two separate power supply connections are interconnected to multiple circuits on the integrated circuit chip to supply equal voltages to individual ones of said multiple circuits from respective ones of said two separate power supply connections, and wherein, upon an open circuit condition on one of said two separate power supply connections, the other one of said power supply connections applies said rated supply voltage to the one power supply connection and to individual ones of said multiple circuits normally supplied by said one power supply connection such that supply leads from the power supply connections to the multiple circuits are still close to the rated supply voltage, said on-chip test comparison circuit then producing said error signal.

Claim 29

An integrated circuit chip comprising: at least two separate power supply connections which carry the same rated supply voltage, means connecting said power supply connections, via respective test leads, to respective input terminals of an on-chip test comparison circuit in order to produce, in a test state of the integrated circuit, an error signal on a signal output of the test comparison circuit when a voltage deviation from a standard voltage difference across said power supply connections exceeds a critical value, and wherein said two separate power supply connections are interconnected to multiple circuits on the integrated circuit chip to supply equal voltages to individual ones of said multiple circuits from respective ones of said two separate power supply connections, and wherein, upon an open circuit condition on one of said two separate power supply connections, the other one of said power supply connections applies said rated supply voltage to the one power supply connection and to individual ones of said multiple circuits normally supplied by said one power supply connection such that supply leads from the power supply connections to the multiple circuits are still close to the rated supply voltage, said on-chip test comparison circuit then producing said error signal.

Claim 30

An electronic apparatus as claimed in claim 21 wherein said test comparison circuit on the integrated circuit chip is adapted to test for faulty connections on the printed circuit board or between the printed circuit board and the integrated circuit chip.