Method and system for storing waveform data of digital oscilloscope as

Abstract

An acquisition memory for storing therein and reading out digital waveform data received from an A/D converter is made up of a dual port serial access memory which stores therein the waveform data in response to a first write clock and reads out the waveform data therefrom in response to a first read clock. A display memory for writing therein and reading out therefrom the waveform data read out from the acquisition memory is made up of a dual port serial access memory which stores therein the data in response to a second write clock different from the first write clock and read out the data therefrom in response to a second read clock different from the first read clock. In a roll operational mode, whenever a predetermined number of pieces of the waveform data are stored in the acquisition memory for each passage of a predetermined period, the waveform data stored in the acquisition memory are read out in an order that the latest waveform data of all data stored in the acquisition memory is last read out therefrom, and eventually data at all addresses of the acquisition memory are read out therefrom. The display memory writes therein the data received from the acquisition memory sequentially at its addresses starting with its header address and reads out from the addresses starting with the header address and then provides the read-out data to a display unit.