| 摘要 |
PURPOSE: A variable mode convertor is provided to provide a shift register used for P/S and S/P convertor commonly and to be possible interface to data bus having various width by using it. CONSTITUTION: A variable mode convertor comprises a data loading unit(10), a bidirectional shift register(20), a latch data selector(30), a counter(40) and a control signal confirmation unit(50). The data loading unit(10) selects optional data bus to be load to the shift register(20) from data bus having various width. The bidirectional shift register(20) receives a parallel data the selected data bus and outputs a serial data or receives the serial data and outputs the parallel data. The latch data selector(30) latches the outputted data from the bidirectional shift register(20) and outputs it to the data bus having prescribed width. The counter(40) counts as the bit number according to the selected data bus width in order that the latch or load is accomplished to appropriate time. The control signal confirmation unit(50) combines a load/latch control signal applied from exterior by logic combination and a mode signal and applies to the bidirectional shift register(20) and the latch data selector(30).
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