Abstract: A semiconductor integrated circuit detecting a change in the internal propagation delay and self-compensating such a change. A combination of semiconductor integrated circuits can self-compensate a change in the total propagation delay of the circuit. There is provided a ring oscillator composed of dummy device elements separate from an actually-used logic circuit portion. The oscillating pulses of the ring oscillator are counted relative to a reference pulse signal. The semiconductor integrated circuit has a delay time compensation control circuit block which generates control data used to compensate the change in the propagation delay based on the difference between the first-counted value and a subsequently counted value. In a combination of semiconductor integrated circuits, the delay time compensation control circuit block may be provided for each channel. Alternatively, the delay time compensation control circuit block may be provided for common use by many channels.

Abstract: A testing device comprises a plurality of pin test portions, each of which is separately provided with a pin pattern controller for controlling the readout of pattern and timing data from pattern and timing memories and a pin instruction memory for storing programs defining the operation procedure of the pin pattern controller. Therefore, the data to be stored in the pattern and timing memories in each of the pin test portions can be in a compressed form, independently of the data to be stored in the pattern and timing memories in the other pin test portions.

Abstract: A waveform formation device according to the present invention comprises a memory storing rise time data and fall time data related to an output waveform, a first timing generator for producing a set signal at a timing related to the rise time data, and a second timing generator for producing a reset signal at a timing related to the fall time data. A flip flop circuit of the device produces an output signal which rises in response to the set signal and falls in response to the reset signal.