Abstract: An LSI testing apparatus of the invention comprises: a plurality of pins P1, P2, . . . PN; function units 10, 11 and 12 which supply the pins with LSI testing signals, which have functions for making judgments on tests, and which are furnished for each of the pins; and clock mask function units 15A and 15B furnished on the input side of each function unit. Upon testing, any unused pin and function are detected so as to mask the clock mask function unit corresponding to the detected pin and function, whereby power dissipation is reduced in terms of unused pins and functions.

Abstract: An LSI testing apparatus of the invention comprises: a plurality of pins P1, P2, . . . PN; function units 10, 11 and 12 which supply the pins with LSI testing signals, which have functions for making judgments on tests, and which are furnished for each of the pins; and clock mask function units 15A and 15B furnished on the input side of each function unit. Upon testing, any unused pin and function are detected so as to mask the clock mask function unit corresponding to the detected pin and function, whereby power dissipation is reduced in terms of unused pins and functions.

Abstract: A waveform and timing generation circuit 28, a skew circuit 30, and a pin driver 32 are provided for each of a plurality of I/O terminals 22 corresponding respectively to a plurality of pins furnished on an LSI. A relay 44 and a loop control circuit 46 are provided to feed an output signal of the pin driver 32 back to an input side of the waveform and timing generation circuit 28. A skew board 100 is used to adjust the skew circuit 30, whereby the initial timing calibration is carried out. With the skew circuit 30 thus adjusted, oscillations are generated over the feedback path, and the number of resulting pulses is counted (to obtain pulse cycles). When the skew circuit 30 is adjusted so that the pulse count above matches the number of pulses generated during oscillations, a simplified form of timing calibration is implemented.