| 摘要 |
A method and apparatus for testing large or very large scale integrated circuit packages is described. The testing equipment required for testing such packages is assumed to lack the number of channels necessary to connect one channel to each input/output of the unit under test. A computer program classifies all input terminals in a plurality of categories, each of which corresponds to particular circuit type and electric network configuration connected to that pin. A unique set of DC levels is defined prior to testing for each class of inputs. These levels are supplied by the tester channels, each of which drives a multitude of input pins that belong to the same category. The assignment of tester channels in the aforementioned arrangement is implemented by means of multiplexers that select for each pin the appropriate set of DC levels, and a memory buffer contained in the tester, with the DC test patterns stored wherein. The bit configuration of each pattern controls plural switching devices that deliver the appropriate DC levels to the terminals of the unit.
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