Macro core testing methods and macro core test equipment

摘要

PROBLEM TO BE SOLVED: To reduce the number of external signal pins and to set many test input/output terminals by providing terminals exclusively for the test mode of macro cores, which have the maximum number of test input/output terminals, as a test mode setting means for a system LSI, on which many macro cores of circuit blocks have designed functions. ;SOLUTION: One macro core referred to as MACRO 0 (type-1 macro core) which has a large number of test input/output terminals, four macro cores referred to as MACRO 1-4 (type-2 macro cores) each of which have a small numbers of test input/output terminals, bidirectional circuits 14 and 16 (third state buffers), a selection circuit 12, and a test mode setting terminal M1 exclusively for MACRO 0, are provided. The test mode setting terminal M1 sets the test mode of MACRO 0, and also functions as the input/output mode control terminals T14 and T16 for external bidirectional terminals TEST 1 and TEST 2, which are used to set the test mode of MACRO 1 through MACRO 4. This raises the upper limit of the numbers of test input/output terminals for mounted macro cores with a limited numbers of external terminals.;COPYRIGHT: (C)2000,JPO