| 摘要 |
PURPOSE:To generate a standard signal as a digital signal directly, by reading out the content of a corresponding address stored in a storage device in synchronizing with an external signal and performing the operation processing, through the command of a switch circuit designating frequency, level and waveform. CONSTITUTION:A storage circuit 10 selects a minimum frequency fe to be generated so that a quotient of a sampling frequency fs divided by the fe is an integer, and as to the standard signal waveform transmitted, the sampling values equal to this quotient are stored as digital values. A storage circuit 11 stores a multiplier for level conversion of a digital signal to a separate address at each level conversion. A readout output of an address designated at the circuit 1 is multiplied 17 with the readout output of the circuit 10 to form a phase-locked loop including a voltage controlling oscillator 23 operated in synchronizing with a synchronizing signal given externally. The readout operation of the circuit 10 and the multiplication operation of the circuit 17 are controlled with a clock generating circuit 26. |
