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can anybody help me how to build a SIPO (Serial In Parallel Out) register just from the RS or RS edge triggered flip flop circuit?

image of sipo

I have tried to build this, but I think its not working. I simulating it in a LOGO!Soft Comfort, and I can not use a different program because its a school project

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Did you forget to tap the outputs? – Ignacio Vazquez-Abrams Oct 16 '12 at 14:51
Why? Other than homework, no one just uses RS flip-flops. – Brian Carlton Oct 17 '12 at 0:13
Shouldn't you be connecting the non-inverting output of each RS flip flop to the S input of the next? – supercat Nov 15 '12 at 18:24
up vote 1 down vote accepted


A shift register does just that. Pull up the datasheet for a 4-bit shift register, like the one above, and it will show you a diagram of the effective logic by which it accomplishes this

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Constructing an SIPO out of edge-triggered registers probably isn't terribly interesting; constructing one out of level-sensitive latches is a bit more interesting. Edge-triggered registers require about twice as much circuitry as level-sensitive ones, but the conventional method of building shift registers from level-sensitive latches requires two latches per bit. It's possible when constructing a large shift register to use some extra circuitry to reduce this burden; the amount of extra circuitry does not depend upon the number of bits in the register, and could easily "pay for itself" with even a 64-bit register (using some extra circuitry to enable groups of four latches to hold three bits).

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