| 摘要 |
PURPOSE:To prevent the increase of an input capacity in an output terminal to prevent delay of the access time by switching the active or nonactive state of an output buffer synchronously with the output signal of a timer to output a signal having the same period from the output buffer. CONSTITUTION:When a mode switching signal is given to a mode discriminating means 1 and the measurement mode is decided a measurement mode signal TEST is outputted. When this signal TEST is outputted, an output buffer control means 2 controls switching between the active state and the nonactive state of an output buffer 4 synchronously with an output signal TM outputted from the timer. Therefore, the output from the output buffer 4 is used to measure the period of the timer output signal because the period of the time when the output signal because the period of the time when the output buffer 4 is activated to go to the low impedance state and the time when it is inactivated to go to the high impedance state is matched with the period of the timer output signal. |
