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Testability of Convergent Tree Circuits
August 1996 (vol. 45 no. 8)
pp. 950-963

Abstract—The testing properties of a class of regular circuits called convergent trees are investigated. Convergent trees include such practical circuits as comparators, multiplexers, and carry-lookahead adders. The conditions for the testability of these tree circuits are derived for a functional fault model. The notion of L-testability is introduced, where the number of tests for a p-level tree is directly proportional to p, rather than exponential in p. Convergent trees that are C-testable (testable with a fixed number of tests, regardless of the tree's size) are also characterized. Two design techniques are also introduced that modify arbitrary tree modules in order to achieve L- and C-testability. Finally, we apply these techniques to the design of a large carry-lookahead adder.

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Index Terms:
Testability, design-for-testability, synthesis-for-testability, C-testability, test generation, regular circuits, iterative logic arrays, tree circuits, functional testing.
Citation:
R.D. (Shawn) Blanton, John P. Hayes, "Testability of Convergent Tree Circuits," IEEE Transactions on Computers, vol. 45, no. 8, pp. 950-963, Aug. 1996, doi:10.1109/12.536237
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