Abstract:
In a first integrated circuit chip contained in a single package along with a second integrated circuit chip, a system includes circuitry on the first integrated circuit chip for receiving address signals from the second integrated circuit chip during normal operation. Circuitry on the first integrated circuit chip generates address signals for use in testing the first integrated chip in a test mode.
Abstract:
Zum Testen von Digitalbausteinen mit Funktionselementen werden diese in Testeinheiten (3) aufgeteilt, die jeweils Eingänge und Ausgänge aufweisen. Die Eingänge der Testeinheiten (3) werden mit wechselnden Testmustern beaufschlagt und die sich dabei ergebenden Testantworten an den Ausgängen der Testeinheiten (3) ausgewertet. Dabei tritt der Effekt auf, dass sich nicht Änderungen an allen Eingängen einer Testeinheit (3) auf einen bestimmten Ausgang dieser Testeinheit (3) auswirken. Für jeden Ausgang der Testeinheit (3) kann ein Kegel (5) definiert werden, dessen Spitze von dem bestimmten Ausgang der Testeinheit (3) gebildet wird und dessen Basis die Eingänge der Testeinheit (3) umfasst, an denen alleine sich Änderungen auf den bestimmten Ausgang auswirken. Erfindungsgemäß wird dabei das Testmuster zum Beaufschlagen der Eingänge der Testeinheit (3) aus Submustern aufgebaut, deren Länge insbesondere ≤ der Anzahl der in der Basis eines Kegels (5) enthaltenen Eingänge der Testeinheit (3) ist. Bei der Auswahl der Submuster können auf Grund deren geringer Länge alle möglichen Kombinationen herangezogen werden, so dass mit geringem Aufwand schnell eine umfassende Funktionsprüfung der Testeinheit (3) durchgeführt werden kann. Diese Testfunktion kann in einem Digitalbaustein insbesondere durch eine Selbsttesteinheit (1) implementiert werden, die den Rest des Digitalbausteins in einen Testmodus umschalten kann und die Testmuster ausgehend von Submustern generieren und zur Beaufschlagung einer Testeinheit (3) in ein Testmusterausgaberegister (2) laden und die sich daraufhin an den Ausgängen der Testeinheit (3) ergebende Testantwort mittels einer Auswerteeinheit (16) auswerten oder zur Auswertung einlesen kann.
Abstract:
A method for applying test patterns to scan chains (26) in a circuit-under-test (24). The method includes providing a compressed test pattern (32) of bits; decompressing the compressed test pattern into a decompressed test pattern of bits as the compressed test pattern is being provided; and applying the decompressed test pattern to scan chains of the circuit-under-test. The actions of providing the compressed test pattern, decompressing the compressed test pattern, and applying the decompressed pattern are performed synchronously at the same or different clock rates, depending on the way in which the decompressed bits are to be generated. A circuit that performs the decompression includes a decompressor (36)such as a linear finite state machine adapted to receive a compressed test pattern of bits. The decompressor decompresses the test pattern into a decompressed test pattern of bits as the compressed test pattern is being received. The circuit further includes scan chains for testing circuit logic, the scan chains coupled to the decompressor and adapted to receive the decompressed test pattern.
Abstract:
A method for applying test patterns to scan chains (26) in a circuit-under-test (24). The method includes providing a compressed test pattern (32) of bits; decompressing the compressed test pattern into a decompressed test pattern of bits as the compressed test pattern is being provided; and applying the decompressed test pattern to scan chains of the circuit-under-test. The actions of providing the compressed test pattern, decompressing the compressed test pattern, and applying the decompressed pattern are performed synchronously at the same or different clock rates, depending on the way in which the decompressed bits are to be generated. A circuit that performs the decompression includes a decompressor (36)such as a linear finite state machine adapted to receive a compressed test pattern of bits. The decompressor decompresses the test pattern into a decompressed test pattern of bits as the compressed test pattern is being received. The circuit further includes scan chains for testing circuit logic, the scan chains coupled to the decompressor and adapted to receive the decompressed test pattern.
Abstract:
A multi-stage algorithmic pattern generator, which generates bit streams for testing IC chips, is comprised of an initial stage, an intermediate stage, and an output stage which are coupled together as a three stage pipeline. The initial stage sequentially generates multiple sets of virtual addresses for a virtual memory in response to a series of instructions from an external source. The intermediate stage sequentially stores each set of virtual addresses from the initial stage and translates the stored set of virtual addresses into a set of physical addresses for an actual memory that is to be tested. The output stage sequentially stores each set of physical addresses form the intermediate stage and generates output signals for testing the memory chips, by selecting bits from the stored set of physical addresses.
Abstract:
An integrated circuit (IC) tester (10) organizes an IC test into a succession of test cycles, each test cycle being subdivided into four segments. The tester (10) includes a separate tester channel (CH1-CHJ) for carrying out a test activity at each IC pin during each segment of the test cycle. The tester (10) also includes a separate pattern generator (PG1-PGJ) for each channel (CH1-CHJ). Each pattern generator (PG1-PGJ) concurrently generates four vectors at the start of each test cycle. Each pattern generator (PG1-PGJ) includes a low speed vector memory (20) storing large blocks of vectors at each address and a cache memory system (28) for caching blocks of vectors read out of the vector memory at a low frequency and then reading vectors in sets of 16 at the higher test cycle frequency. A vector alignment circuit (30) selects from among the cache memory (28) output vectors to provide the four vectors to the channel for the test cycle.
Abstract:
The invention relates to an integrated circuit comprising a self-test device (B) for executing a self-test of the integrated circuit which has a control output (CTR). The integrated circuit also comprises a program memory (MI) which is connected to the self-test device and which is provided for storing at least one test program (P) that is supplied from outside the integrated circuit. Said test program is ran by the self-test device during the execution of a self-test. The self-test device (B) controls the loading of the respective test program to be ran into the program memory from outside the integrated circuit via the control output (CTR) thereof.
Abstract:
A test pattern generator with wich an expected value can be easily generated with respect to an arbitrary initial value when testing a memory provided with write enable/disable control for every bit. The test pattern generator is provided with an XOR controller (131) which generates a control signal in accordance with the signal from an instruction memory (112), an AND gate (123) which receives the output signal of the controller (131) through one input terminal and the inverted output signal of a data generator B (15) through the other input terminal, and an exclusive OR gate (121) which receives the output of the AND gate (123) through one input terminal and the output signal of a data generator A (14) through the other input terminal.
Abstract:
Multiple embedded RAMs are tested, one at a time, for stuck at faults, including multibit faults. Parity for the RAMs is also tested and tests are performed for marginal read/write problems by changing clock frequency. A lockup mechanism yields the failing address. To accomplish the test, the RAM write address is written as data and then read back. Since the address is written as data, the expected result in a read operation is known. Thus, failures are predicted by comparing the reference address in a read cycle with the data read from the RAM. This operation is then repeated by writing the inverse write address as data. Through the two sets of write/read/compare operations, every RAM bit is toggled. After performing the two operations for one RAM, the procedure is repeated for each RAM until all have been tested. In a second embodiment, multiple embedded RAMs are tested simultaneously with the same address and data lines going to all RAMs. As with the first embodiment, testing is for stuck at faults, including multibit faults; parity for the RAMs is also tested as re-marginal read/write problems. The data patterns include the write address as data, inverse write address as data, or random data. In the second embodiment, the same data is simultaneously written into multiple RAMs, followed by a read/compare cycle. The comparison determines whether there is an error. As in the first embodiment, a look-up mechanism yields the failing address. Since, in this second embodiment, it does not matter what data is written to the RAMs, this embodiment provides the additional capability of utilizing random data to test for additional fault conditions.
Abstract:
Electronic devices (320) are provided which comprise a digital logic circuit (101 ) and a test module (322) adapted to receive test parameters from a remote test management device (310), generate test patterns based on the test parameters, apply the test patterns to the digital logic circuit, receive test responses from the digital logic circuit, compact the test responses into a test signature, and either transmit the test signature to the remote test management device or determine a test result based on a comparison of an expected signature received from the remote test management device with the test signature. Further provided are remote test management devices comprising means adapted to acquire test parameters suitable for generating test patterns for a digital logic circuit, acquire an expected signature corresponding to the test patterns, transmit the test parameters to at least one electronic device comprising the digital logic circuit, and either receive a test signature from the at least one electronic device and determine a test result based on a comparison of the expected signature with the test signature, or transmit the expected signature to the at least one electronic device.