| 摘要 |
PURPOSE:To easily generate test data by preventing a division circuit from becoming larger when diagnosing an LSI. CONSTITUTION:A division circuit 10 is constituted of logic gate groups 14, 15, and 16 surrounded by edge pins 11, an input flip-flop 12, and an output flip-flop 13 of an LSI 1. Test data control circuit modules 20 and 20' are inserted between the logic gate groups 14/16 and 15/16 and the division circuit 10 is further divided into finely divided circuits 30, 40, and 50, thus making smaller a circuit for which test data are generated. At the time of diagnosis, a test data control circuit 100 writes the output data of a group of pre-stage gates into the module 20 or 20', reads the data by scan-out, writes the data by scan-in, and outputs the data to a group of succeeding-stage gates. At the time of actual operation, the modules 20 and 20' are bypassed. |
