Functional block for integrated circuit, semiconductor integrated circuit, method for testing semiconductor integrated circuit, and method for designing semiconductor integrated circuit

Abstract

A semiconductor integrated circuit (1) includes first, second and second functional blocks (10, 20 and 30). The first, second and second functional blocks (10, 20 and 30) are coupled together via an inter-block signal line (2). The first functional block (10) includes: a logic circuit (11); a test data output circuit (12), which operates during testing and outputs a predetermined test data pattern; a testing standby circuit (14), which is connected between a selector (13) and an external bidirectional pin and makes the functional block enter a standby state during testing; a tristate buffer (15) that is made to have a high impedance by the testing standby circuit (14); and a decision result output circuit (16), which receives the test data pattern from the second functional block, compares the received test data pattern to an expected value stored therein, and outputs a decision result to a decision result signal line (5).

Description

[0001] The present invention relates to a functional block for integrated circuit (hereinafter, simply referred to as an "IC functional block") implemented as a macro cell including a self-diagnosis circuit for detecting a fault between functional blocks, for example. The present invention also relates to a semiconductor integrated circuit that has been designed using the IC functional block and to respective methods for testing and designing the semiconductor integrated circuit.[0002] In recent years, demand for designing a semiconductor integrated circuit more efficiently by implementing the circuit as a combination of functional blocks such as macro cells has been increasing. If a semiconductor integrated circuit is designed by combining a plurality of functional blocks with each other, however, there arises a problem in how to test a signal line interconnecting these functional blocks together. To solve this problem, according to a conventional technique, the operations of a pai...

AI Technical Summary

Benefits of technology

[0012] According to the first IC functional block, a test data output circuit for outputting test data is provided within the IC functional block. Thus, if a semiconductor integrated circuit is constructed of the block and another IC functional block including a circuit that can receive the test data and compare it to an expected value, then the test data can be transmitted and received even when the user does not know much about the internal configuration and operation of the IC functional blocks. Accordingly, even if IC functional blocks are combined or the circuit sizes of the IC functional blocks are huge, a test among the IC functional blocks can be carried out easily and accurately in the semiconductor integrated circuit.

[0097] As can be understood, even if the user does not know much about the configurations (i.e., the circuit or functional configurations) of the respective functional blocks 10, 20 and 30 or if the circuit sizes are too huge to produce test data with ease, the inter-block signal line 2 can be tested easily and accurately according to this embodiment.

Problems solved by technology

If a semiconductor integrated circuit is designed by combining a plurality of functional blocks with each other, however, there arises a problem in how to test a signal line interconnecting these functional blocks together.

However, if the first and second functional blocks 501 and 502 are combined and reused, it might be difficult for the user to produce test data patterns that should be propagated through the respective functional blocks.

This is because the user is not acquainted with the internal configurations and operations of the functional blocks.

Also, if the circuit sizes of the first and second functional blocks 501 and 502 are huge, then it is extremely complicated and very difficult to produce test data patterns that should be propagated through the respective functional blocks.

Thus, a large number of clock cycles should be consumed for that purpose, and it is difficult to supply the test data patterns rapidly and continuously enough to detect a fault promptly.

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