| 摘要 |
PURPOSE: To eliminate a need of adjustment after assembling by comparing the frequency of a picture display clock with that of a system clock to perfrom adjustment by a program. CONSTITUTION: The output obtained by dividing the frequency of the clock outputted from an oscillation circuit for picture display control by a frequency division ratio set by the program of a microcomputer 8 and the output obtained by dividing the frequency of the system clock of the microcomputer 8 by a prescribed frequency division ratio are compared with each other by a phase comparator 7. Several oscillation resistances incorporated in the oscillation circuit for picture display control are switched by the comparison result to automatically determine the oscillation frequency of a display part, thereby controlling the oscillation frequency for display to a specific value. Thus, the frequency to a desired display position is automatically set by the private circuit and software of the microcomputer to eliminate the need of adjustment after assembling. |
