Logic circuit board with a clock observation circuit

摘要

This logic circuit board with a clock observation circuit comprises a plurality of logic circuit IC chips and a clock supply IC chip to supply clock signal to such logic circuit IC chips mounted on a printed wiring board. The logic circuit IC chips are respectively connected to the clock supply IC chip via clock supply wires to propagate clock signal, all of which have the same length. Each of the logic circuit IC chips is provided with an observation terminal for clock signal observation, and the clock supply IC chip is provided with an external terminal for clock signal observation. Propagation time adjustment means comprising a delay circuit for adjustment of clock signal propagation time is provided between the clock supply IC chip and the external terminal. Then, the delay in propagation of clock signal is adjusted so that the phase shift of the clock signal observed at the external terminal is the central shift value between the maximum and the minimum shifts of the clock signal observed at the observation terminals of the logic circuit IC chips.