| 摘要 |
<p>PURPOSE:To attain ease of identification even if the number of parallel data is large by providing an oscillator operated independently and asynchronously with a word clock for an internal clock in case transmitting a serial data signal which is converted from a parallel data. CONSTITUTION:Data loading of a shift register is executed by a frame pulse. When the data is loaded, an output of a shift register goes to ''0'', and when the frame pulse goes to ''0'' level, the shift operation by a clock signal CLK from a crystal oscillator circuit 2 is started, and a serial data is outputted in succession to a start pulse as a synchronizing pulse in synchronizing with the internal clock generated by the condition of ''1'' level of a start pulse generating signal STAS. In the figure, 4 is a frame pulse extracting circuit to extract the frame pulse from a serial data signal SD, and the circuit extracts the pulse by utilizing the fact that the width of the frame pulse is different from the width of the other data pulses. Since the internal clock component is extracted among the serial data, the clock having the same frequency as the internal clock at the transmission side is obtained.</p> |
