Method for testing an integrated circuitry and an integrated circuit having a plurality of functional components and having junction/switch

Claims

We claim:

1. A method for testing electronic circuitry having a plurality of functional components interconnected by primary handshake communication channels for communication of in-channel signalizations each primary handshake communication channel having a first terminating end and a second terminating end, each functional component having at least one of i) an active port and ii) a passive port, said first terminating end of each of said primary handshake communication channels terminating at an active port of one of said functional components which functional component active port initiates a communication and said second terminating end of each of said primary handshake communication channels terminating at a functional component passive port awaits the communication, said method comprising the steps of:

providing at least one of said primary handshake communication channels with an in-breaking junction which divides said at least one primary handshake communication channel into a string of secondary handshake communication channels which string serially couples the two functional components having the active and passive ports on said at least one primary handshake communication channel together forming a first test component for testing said at least one primary handshake communication channel and said functional components during a test mode, said junction having a passive port and an in-channel passive port and forming part of the handshake communication in said at least one primary handshake communication channel when not in said test mode; and

breaking in via said passive port of said junction with a first test signalization, the first test signalization being an alternative to any of the in-channel communication directed towards said in-channel passive port of said junction, and wherein the first test signalization tests any component having a passive port on said at least one primary handshake communication channel and any channel part between said any component and said first test component.

2. A method as claimed in claim 1, wherein said electronic circuitry is a single integrated circuit, and the step of providing an in-breaking junction is performed on a primary handshake communication channel within the integrated circuit.

3. A method as claimed in claim 1, for testing said electronic circuitry having a plurality of integrated circuits, further including the step of

assigning to any channel crossing any border between separate integrated circuits a dummy functional component while at either side of said border creating a separate channel as a respective one of said primary handshake communication channels.

4. A method as claimed in claim 3, further including the step of executing an interconnection test by means of inbreaking and outbreaking respective test signalizations on said respective separate channels pairwise joined by an associated said dummy functional component.

5. The method as claimed in claim 1, wherein the communication channels and functional components are coupled together along a path and wherein the step of breaking in with a first test signalization tests any channel in the path of the first test signalization.

6. An integrated circuit comprising a plurality of testable functional components each having at least one of an active communication initiating port and a passive communication awaiting port interconnected by primary handshake communication channels for communication of in-channel signalizations each primary handshake communication channel having a first terminating end terminating at an active communication initiating port and a second terminating end terminating at a passive communicating awaiting port of said functional components and at least one of said primary handshake communication channels being provided with at least one of i) an inbreaking junction and ii) an outbreaking switch, thereby forming at least one test component that at other times than testing just forms part of the in-channel handshaking and wherein the at least one test component divides said at least one primary handshake communication channel into a string of secondary handshake communication channels which string serially couples together the two functional components having the active and passive communication ports on said at least one primary handshake communication channel, any of said junctions having a passive channel port for in-channel initiated communications and a passive test port for externally initiated test communications, and a active channel port for propagating both said types of initiated communications, any said switch having a passive channel port for in-channel initiated communications, a active channel port for in-channel propagation of these initiated communications and an active test port for extra-channel propagation of these initiated communications and a passive control port for selecting for propagation between said active channel port and said active test port.

7. A circuit according to claim 6, wherein a single primary handshake communication channel includes both a junction and a switch that together constitute a test component pair, thereby allowing both inbreaking and outbreaking test facilities for said single primary handshake communication channel.

8. A circuit as claimed in claim 6, wherein a dummy functional component is assigned to a border of said integrated circuit which creates a further handshake communication channel terminating at said dummy functional component for attachment to a further integrated circuit and said further handshake communication channel being provided with a junction and a switch as a test component pair.

9. A circuit as claimed in claim 6, wherein said functional components are clockless on a granularity level of a channel handshake.

10. A circuit as claimed in claim 6, further including self-test means for receiving an external activation signal and an aggregate test signal including a control signal, said self-test means including

developing means for developing from said aggregate test signal various elementary test signalizations and control signalizations for said junctions and switches and

aggregating means for aggregating said externally initiated test signalizations and said second test signalizations to an aggregate result signal for inspection outside said circuit.

11. A circuit as claimed in claim 6, wherein said junction has an electronic part in common with one of said functional components at which a primary handshake communication channel terminates.

12. A circuit as claimed in claim 6, wherein said switch has an electronic part in common with one of said functional components at which a primary handshake communication channel terminates.

13. A circuit as claimed in claim 6, wherein one of said functional components includes acknowledge means for upon completion of said testing outputting an acknowledge signal extraneous to said in-channel signalizations occurring during non-test mode from one of said functional components.

14. A circuit as claimed in claim 6, further including a testable variable-presenting functional component.

15. A circuit as claimed in claim 6, wherein said electronic circuitry includes a multiplicity of interconnected integrated circuits.

16. A circuit as claimed in claim 6, wherein a single test channel serpentines through a plurality of junctions and switches for operating as a two-phase handshake channel.

17. A method of testing asynchronous solid-state electronic circuitry having a plurality of functional components interconnected by primary handshake communication channels for communication of in-channel signalizations, each primary handshake communication channel having a first terminating end and a second terminating end, each functional component having at least one of i) an active port and ii) a passive port, said first terminating end of each of said primary handshake communication channels terminating at an active port of one of said functional components which functional component active port initiates a communication and said second terminating end of each of said primary handshake communication channels terminating at a passsive port of one of said functional components which functional component passive port awaits the communication, said method comprising the steps of:

providing a first primary handshake communication channel with an inbreaking junction which divides said first primary handshake communication channel into a string of secondary handshake communication channels which string serially couples the two functional components having the active and passive ports on said first primary handshake communication channel together and a second primary handshake communication channel with an outbreaking switch, which switch divides said second primary handshake communication channel into a string of secondary handshake communication components which string serially couples the two functional components having the active and passive ports on said second primary handshake communication channel together said junction and said switch forming a set of test components for testing said first and second primary handshake communication channels and said functional components positioned thereon during a test mode and forming part of the handshake communication in said first and second primary handshake communication channels when not in said test mode, said junction having a passive port and an in-channel passive port, said switch having a control port, an active extra-channel port and a further active port;

breaking in via said passive port of said junction with a first test signalization, the first test signalization being an alternative to any of the in-channel signalizations directed towards said in-channel passive port of said junction; and

breaking out via said active extra-channel port of said switch a second test signalization under control of an external control signal at said control port of said switch, the second test signalization being an alternative to any further in-channel signalization via said further active port of said switch and wherein the first and second test signalizations test (a) any component with a passive port on said first primary handshake communication channel, (b) any component with an active port on said second primary handshake communication channel and, (c) any channel part between i) said in breaking junction and said any component with a passive port on said first primary handshake communication channel ii) any component with a passive port on said first primary handshake communication channel and any component with an active port on said second primary handshake communication channel and iii) any component with an active port on said second primary handshake communication channel and said outbreaking switch.

18. A method as claimed in claim 17, further including the step of providing at least one primary handshake communication channel with both a junction and a switch as a test component pair thereby allowing both inbreaking and outbreaking test facilities for said at least one primary handshake communication channel.

19. A method as claimed in claim 17, further including the steps of:

controlling said switch for breaking out the second test signalization during said test mode; and

controlling said switch for propagating the in-channel signalization via said further active port of said switch when not in said test mode.

20. A method as claimed in claim 17, for executing a plurality of tests on said functional components and further including the steps of:

presenting an aggregate test signal to said circuitry including aggregate control signals;

extracting from the aggregate test signal the first test signalization; and

extracting from the aggregate test signal control signals for controlling said switch.

21. A testing circuit for electronic circuitry having a plurality of testable functional components interconnected by primary handshake communication channels for communication of in-channel signalizations, wherein a first functional component includes an active port and a second functional component includes a passive port and wherein a primary handshake communication channel has a first terminating end terminating at an active port of a functional component and a second terminating end terminating at a passive port of a functional component, wherein said active port initiates a communication and said passive port awaits said communication, said testing circuit comprising:

an inbreaking junction provided on a first primary handshake communication channel which divides said first primary handshake communication channel into a string of secondary handshake communication channels which string serially couples the two functional components having the active and passive ports on said first primary handshake communication channel together for testing said primary handshake communication channel functional components during a test mode, said junction having a passive port for awaiting externally initiated test signalizations, an in-channel passive port for awaiting in-channel signalizations and an active port for propagating the in-channel signalizations such that during a non-test mode said junction forms part of the handshake communication in said first primary handshake communication channel, said passive port of said junction for awaiting communication of the externally initiated test signalization during the test mode, and said active port of said junction for propagating the externally initiated test signalization instead of the in-channel signalizations during the test mode; and

an outbreaking switch provided on a second primary handshake communication channel which switch divides said second primary handshake communication channel into a string of secondary handshake communication channels, which string serially couples the two functional components having the active and passive ports on said second primary handshake communication channel together, said switch and junction forming a set of test components, said switch having an active extra channel port for breaking out of said second primary handshake communication channel a second test signalization, a further active port for propagating the in-channel signalization during a non-test mode and a control port for receiving control signalizations and for selecting between activating said active extra channel port and activating said further active port.

22. A circuit according to claim 21, wherein at least one of the first and second primary handshake communication channels includes both a junction and a switch that together constitute a test component pair, thereby allowing both inbreaking and outbreaking test facilities for said at least one primary handshake communication channel.

23. A circuit as claimed in claim 21, wherein a dummy functional component is assigned to a border of said integrated circuit which creates a further primary handshake communication channel terminating at said dummy functional component for attachment to a further integrated circuit and said further primary handshake communication channel being provided with a junction and a switch as a test component pair.

24. A circuit as claimed in claim 21, further including self-test means for receiving an external activation signal and an aggregate test signal including a control signal, said self-test means including

developing means for developing from said aggregate test signal various elementary test signalizations and control signalizations for said junctions and switches, and

aggregating means for aggregating said externally initiated test signalizations and said second test signalizations to an aggregate result signal for inspection outside said circuit.

25. A circuit as claimed in claim 21, wherein said junction includes an electronic part in common with one of said functional components.

26. A circuit as claimed in claim 21, wherein said switch includes an electronic part in common with one of said functional components.

27. A circuit as claimed in claim 21, wherein one of said first and second functional components includes acknowledge means for, upon completion of said testing, outputting an acknowledge signal extraneous to said in-channel signalizations occurring during non-test mode from one of said first and second functional components.

28. A circuit as claimed in claim 21, wherein said electronic circuitry includes a multiplicity of interconnected integrated circuits.

29. A circuit as claimed in claim 21, wherein a single primary handshake communication channel serpentines through a plurality of junctions and switches for operating as a two-phase primary handshake channel.

30. A method of testing electronic circuitry having a plurality of functional components interconnected by primary handshake communication channels for communication of in-channel signalizations, each primary handshake communication channel having a first terminating end and a second terminating end, each functional component having at least one of i) an active port and ii) a passive port, said first terminating end of each of said primary handshake communication channels terminating at an active port of one of said functional components which functional component active port initiates a communication and said second terminating end of each of said primary handshake communication channels terminating at a passive port of one of said functional components which functional component passive port awaits the communication, said method comprising the steps of:

providing a first primary handshake communication channel with an inbreaking junction and an outbreaking switch which divide said first primary handshake communication channel into a string of secondary handshake communication channels, which string serially couples the two functional components having the active and passive ports on said first primary handshake communication channel together, said junction and said switch forming a set of test components for testing said first primary handshake communication channel and said functional components coupled to said first primary handshake communication channel during a test model and wherein said junction and switch form part of the handshake communication in said first primary handshake communication channel when not in said test mode, said junction having a passive port and an in-channel passive port, said switch having a control port, an active extra-channel port and a further active port;

breaking in via said passive port of said junction with a first test signalization, the first test signalization being an alternative to any of the in-channel signalizations directed towards said in-channel passive port of said junction; and

breaking out via said active extra-channel port of said switch a second test signalization under control of an external control signal at said control port of said switch, the second test signalization being an alternative to any further in-channel signalization via said further active port of said switch and wherein the first and second test signalizations test any component with a passive port on said first primary handshake communication channel, any component with an active port on said first primary handshake communication channel, and said first primary handshake communication channel.

31. A testing circuit for electronic circuitry having a plurality of testable functional components interconnected by primary handshake communication channels for communication of in-channel signalizations, wherein a first functional component includes an active port and a second functional component includes a passive port and a primary handshake communication channel has a first terminating end terminating at said active port and a second terminating end terminating at said passive port, wherein said active port initiates a communication and said passive port awaits said communication, said testing circuit comprising:

an inbreaking junction provided on said primary handshake communication channel for testing said primary handshake communication channel and said functional components during a test mode, said junction having a passive port for awaiting externally initiated test signalizations, an in-channel passive port for awaiting in-channel signalizations and an active port for propagating the in-channel signalizations such that during a non-test mode said junction forms part of the handshake communication in said primary handshake communication channel, said passive port of said junction for awaiting communication of the externally initiated test signalization during the test mode, and said active port of said junction for propagating the externally initiated test signalization instead of the in-channel signalizations during the test mode; and

an outbreaking switch also provided on said primary handshake communication channel, said junction and said switch divide said primary handshake communication channel into a string of secondary handshake communication channels which string serially couples said first and second functional components together, said switch and junction forming a set of test components, said switch having an active extra channel port for breaking out of said primary handshake communication channel a second test signalization, a further active port for propagating the in-channel signalization during a non-test mode and a control port for receiving control signalizations and for selecting between activating said active extra channel port and activating said further active port.

FIELD OF THE INVENTION

The invention relates to a method for testing electronic circuitry with a plurality of functional components interconnected by handshake channels. Testability of integrated circuits has been approached in various ways, inter alia as dependent on circuit technology, fault model, and test provisions that may be present or absent, physically as well as notionally. Earlier provisions include scan test or LSSD, boundary scan test, both of these approaching the circuit as a single black box. U.S. Pat. No. 4,656,592 to the same assignee teaches the breaking up of complicated circuits into partial circuits that maintain mutual synchronization through a handshaking procedure. This would allow for blockwise testing in a quite specific environment wherein the partial circuits operate synchronously and only the interaction between the various circuits is executed via handshakes. During development of the present invention it has occurred that widespread use of handshaking functional components is a preferred method to keep development of asynchronous circuitry manageable. Given such asynchronous realization, test generation remains a problem that more or less explodes exponentially with the size of the circuit, causing rather simple circuits to need an astronomical number of test patterns and/or test time. The present invention presents a solution in that it envisages breaking-into and breaking-out from the channels. In particular, a channel is herein understood to be a point-to-point connection that has an active port on its first end, and a passive port on its second end. The active/passive notion relates to activities on the communication protocol level, and not on the data transfer direction. This means that data may go from the passive port side to the active port side. By itself, no data transfer need even occur, if the only object of the communication is, e.g. synchronization.

SUMMARY TO THE INVENTION

Amongst other things, it is an object of the present invention to provide an infrastructure for structural testing of handshake circuits at a low level of organizational complexity. According to the present environment, a handshake circuit is a network of asynchronous circuit blocks that exhibit mutual synchronization and may exchange information.

According to one of its aspects, the invention provides a solution as a method for testing electronic circuitry having a plurality of functional components interconnected by handshake communication channels, each channel terminating at respective functional components. The termination being at an active port of a functional component from which a communication is initiated and a passive port of a functional component where such communication is awaited, respectively. The method provides one of the channels with an inbreaking junction thereby forming a first test component that at times other than testing the junction just forms part of the in-channel handshaking. The method includes breaking in via a passive port of the junction with a first test signalization which first test signalization is an alternative to any in-channel signalization towards the in-channel passive port of the junction. The first test signalization representing the test signalization for the channel in a test on any component with a passive port on the channel and any channel part between the any component and the test component. The design-for-testability may be embedded in a silicon compilation organization as per U.S. Pat. No. 5,005,136, issued Apr. 2, 1991, to the same assignee, which reference is referred to in particular for corresponding terminology. It has been found that inbreaking via a junction would even in the absence of any data transfer, by means of a synchronization signal returned, allow for executing a test. If the synchronization is not returned, this could signal a failed test. It should be noted that the present method need not necessarily have the sequence: provide test pattern, execute test, extract result pattern. Presentation of a test pattern may or may not result in a returned synchronization signal. A result pattern may emanate from executing a test by means of a test pattern that had been stored earlier. The test may be a self-test, wherein control is temporarily effected locally without external intervention.

More comprehensively, the invention provides a method for testing electronic circuitry having a plurality of functional components interconnected by handshake communication channels each terminating at respective functional components. The termination being at an active port of a functional component from which a communication is initiated and a passive port of a functional component where such communication is awaited, respectively. The method provides one or more of the channels with an inbreaking junction and/or one or more of the channels with an outbreaking switch thereby forming a set of test components that at times other than testing just form part of the in-channel handshaking. The method includes the step of breaking in via a passive port of a first channel's junction with a first test signalization. The first test signalization is an alternative to any in-channel signalization towards the in-channel passive port of the junction. Under control of an external control signal to a control port of a switch on a second channel, the method further includes breaking out from the second channel a second test signalization via an active extra-channel port of the switch. This breaking out of a second test signalization ceases any further in-channel signalization via an active further port of the second channel's switch, the first test signalization being the test signalization for the first channel in a test on any component with a passive port on the first channel and any channel part between such a component and the junction. The second test signalization being the test signalization for the second channel in a test on any component with an active port on the second channel, and any channel part between such components and the switch. Generally, a complicated circuit will need a plurality of junctions and a plurality of switches. In certain circumstances, one category of the two could be absent; like the junction, a switch could work in isolation: in case of a test, internal control could produce or not produce the result data at the switch's output.

The present invention makes the problem simpler by allowing it to be broken down into parts: insertion of such inbreaking and outbreaking facilities leads to a smaller depth of the state diagrams with respect to testing. It should be noted that both the first and the second test signalizations may comprise respective composite signals and/or multibit patterns, and moreover, neither of them need to contain data inasmuch as either one may comprise only communication primitive signals. It should be noted that U.S. Pat. No. 4,656,592 does not teach any specifics as to how the test would effectively be executed on the level of the synchronization primitives.

Advantageously, the method provides at least one channel with a switch that in its test signalization is controlled both in test mode for breaking out of in-channel signalizations within the at least one channel as well as in non-test mode for continuing in-channel signalizations. Under non-test situations this would allow for standard functionality. Advantageously, the method provides at least one channel with both a junction and a switch as a test component pair thereby allowing both inbreaking and outbreaking test facilities for the at least one channel. The contiguous junction and switch constitute a concrete or physical test component pair. By having the span of such concrete test component pairs overlapping each other, any part of the channel now covered by such overlapping is rendered testable. In particular, apart from wires, the channel may comprise such elements as buffers or invertors, that are now also rendered testable. The methodology deployed can be applied on various levels, such as on the board level, within a single chip, as well as on-chip between blocks of various levels of complexity. Moreover, it can be used as a partial approach, such as for specifically testing those parts of the circuits that are difficult to control or to observe otherwise.

Advantageously, the invention provides a method for executing a plurality of tests on respective functional components by presenting to the circuitry an aggregate test signal including aggregate control signals, extracting therefrom a first test signalization for inbreaking onto various junctions and also extracting respective external control signals for presentation to various switches and also extracting respective second test signalizations for breaking out from various switches. This allows for an external access either at a narrower path width or at a lower amount of data transfer. The organization for a proper ordering, extraction, aggregation of the various test and control signals may be obtained from the organizational structures that are available for handshake circuits, such as for (de)multiplexing, parallel composition, and sequential composition structures as disclosed in U.S. Pat. No. 5,005,136. Additionally, translating tables, hashing technology and signature generation could be used in various instances. The provision of various junctions and switches in the circuitry's communication channels is a direct hardware mirroring of the design for testability and the test method itself. Moreover, the provision of respective test components can be used in a self-test organization. Self-test is herein defined in that an aggregate test signal provided from outside is used in conjunction with various in-circuitry prepresented or prestored test signalizations, whether explicit or implicit, to execute a plurality of elementary test operations, after which a plurality of elementary test results are joined, signatured, or otherwise evaluated to signal an overall test evaluation outside the circuitry tested. By itself, such self-test principle with respect to a static RAM memory has been described in U.S. Pat. No. 5,325,367, EP published specification 350,538, to the assignee of the present application, herein incorporated by reference.

It is particularly advantageous of the invention, to test the electronic circuitry having a plurality of integrated circuits, by assigning to any channel crossing any border between separate integrated circuits a dummy functional component at the border for creating at either side of the border a separate channel as a respective one of the handshake channels. If the circuitry consists of more than one separate integrated circuit, it is not known in advance what the "neighbor" circuit would be. It could have the test provisions according to the invention, or not. And even in the positive case the two channels could have somewhat different protocols on a level that would interfere with the testing, although this would not be the case for standard handshaking. In particular, the latter provision would permit execution of a boundary or interconnection test, as an alternative approach to the boundary scan test standard according to JTAG, now IEEE 1149.1. On another level, the present invention can be used for test features according to self-test principles at various levels of complexity.

According to an advantageous aspect, an integrated handshake circuit testable according to the present invention, comprises a plurality of testable functional components that are interconnected by handshake communication channels each terminating at respective functional components. The termination being at an active communication initiating port of the functional component and a passive communication awaiting port of the functional component, respectively. Part of the channels being provided with an inbreaking junction or an outbreaking switch, thereby forming a set of test components that at times other than testing just form part of the in-channel handshaking. Any of the junctions having a first passive channel port for in-channel initiated communications and a second passive test port for externally initiated test communications, and a first active channel port for propagating both of the types of initiated communications. Any switch having a third passive channel port for in-channel initiated communications, a second active channel port for in-channel propagation of these initiated communications and in each one of at least part of the switches a combination of a third a