PERFORMANCE MEASURING INSTRUMENT

PURPOSE:To keep a memory capacity constant, by generating an address based on a measured data part decided based on the value of a sampling interval register and the content of a start address register, and incrementing data at the address of a memory. CONSTITUTION:The titled device is equipped with the sampling interval register 4 which holds the value of a sampling interval, and the start address register 5 which holds a start address, and a processor 2 is provided with a means to separate the measured data part decided by the value of the sampling interval register out of measured data sent from a performance measuring part 1, a means which generates the address based on the measured data part and the content of the start address register 5, and a means which increments the data at the address of a memory 3 shown as the address. In such a way, it is possible to keep the memory capacity constant and also, to prevent accuracy from being lowered even when a sampling time is shortened.