| 摘要 |
<p>A computing means is provided which has its instruction execution synchronized to a reference signal. The computing means executes instructions in instruction cycles synchronously related to a clock signal. The clock signal is generated by means which can control its phase and frequency in response to a control signal. The computing means generates a comparison signal each time a predetermined number of instruction cycles have occurred. A comparison means compares the phase and frequency of the comparison signal to that of a reference signal from a source and generates the control signal in response. Alternatively, characters are displayed on the image display device of a television system by means of a microprocessor. The microprocessor is embodied on an integrated circuit and executes instructions in instruction cycles in time relationship with a clock signal. The clock signal is generated by means which can control its phase and frequeny in response to a control signal. A synchronizing means generates the control signal in response to the clock signal and a television synchronizing signal from a source so that the instruction cycles are synchronized with the television synchronizing signal. The microprocessor generates character pulses at a rate proportional to the instruction cycles from data signals corresponding to the character from a source. Means couple the character pulses to the image display device to display the characters.</p> |
