74LS194
簡介
74LS194為一個具有paralle load，且能雙向shift的暫存器。
簡圖

真值表

Mode Function

Clear Clock S1 S0

0 X X X Clear outputs to 0

1 正邊緣觸發 0 0 No change in output

1 正邊緣觸發 0 1 Shift right in the direction from QA to QD. SIR to QA

1 正邊緣觸發 1 0 Shift left in the direction from QD to QA. SIL to QD

1 正邊緣觸發 1 1 Parallel-load input data

Mode				Function
Clear	Clock	S1	S0	Function
0	X	X	X	Clear outputs to 0
1	正邊緣觸發	0	0	No change in output
1	正邊緣觸發	0	1	Shift right in the direction from QA to QD. SIR to QA
1	正邊緣觸發	1	0	Shift left in the direction from QD to QA. SIL to QD
1	正邊緣觸發	1	1	Parallel-load input data