Question Regarding IC pin numbering and logic gates

AI Thread Summary
The discussion centers on assigning IC pin numbers for logic gates in a homework assignment involving integrated circuits. The user expresses confusion about how to connect inputs and outputs based on a provided diagram, specifically regarding the meaning of labels like A, B, Cin, S, and Cout. Participants clarify that each integrated circuit has a specific configuration of logic gates, and understanding the pin-out for the chosen IC is crucial for proper wiring. They emphasize the importance of reading the logic diagram and suggest referring to data sheets for specific ICs, such as the 7400 series, to determine pin assignments. Ultimately, the user successfully completed the task of building a one-bit full adder, indicating progress in understanding integrated circuits.
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Homework Statement


http://i.imgur.com/k8nq4HZ.jpg
So I need to assign IC pin numbers to the input and output of the logic gates.

Homework Equations



None

The Attempt at a Solution



I only have limited knowledge on integrated circuits as a whole, so I'm pretty confused altogether. I know that I can hook up inputs and outputs onto my IC, and then produce a result, but how do I know which pin numbers to use?

Edit: I learned a bit more about integrated circuits and logic gates over the internet, so I understand that each integrated circuit has a built in system of logic gates, and the pins represent either input, output, ground, or voltage source. However, I am still confused about what to do for this, I know that I'll probably be using multiple integrated circuits and using wires to replicate the situation in the picture, but I'm confused about a few things.
On a breadboard, what exactly is A, B, Cin, S, and Cout?
Also, is this assignment as simple as I think it is? Just wiring together integrated circuits according to the diagram?
 
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Your picture shows a series of logic gates. look up logic symbol images, to see the differences. If you have a specific IC chip in hand that you know has these specific logic gates, then you have to determine which pairs of pins correspond to what types of gates.

While it has been a while since I played with logic chips, the ones I remember were of a type- one chip was all AND gates, another was OR gates, and so on. if this is the case, you will need a set of chips, then get each ones' pin-out configuration, and that will point you toward the wiring of them.

As for the letters; while I do cannot know what specifically they refer to in your situation, by the setup, A and B are choices (maybe switches, push buttons, etc) that determine if Cin reaches Cout or S is enabled.

Reading the logic shown from left to right and top down should enable you to determine what outcome you get for a given input. for example: If you choose ONLY A or ONLY B or ONLY Cin, you get S. any combination of two or three of the options negates that possibility - that comes from the two XOR (exclusive OR) gates at the top. Similarly you can determine what specific set (or sets) of selections allow for Cout to occur.

Hope this helps, and does not state what you already know. *grin*
 
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Logic gates are available in many different forms. Have you been told what family of devices to use or what technology?

For decades you could/can buy logic gates in "packages" of 2 to 8 gates all of the same type on one chip. A common family is the 7400 series...

http://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuits

See the table.

For example a 7402 contains four NOR gates, each having two inputs and one output.

If you look at the data sheet for it will give you the pin numbers for the inputs and outputs.

Remember that the inputs of unused (spare) gates should not be left unconnected.

PS: In general it doesn't matter which of the gates within a package you use. However sometimes you choose one instead of another in order to make the external wiring easier/shorter. For example when connecting the output of one gate to the input of another (of the same type) it helps if they are in the same package and/or the pins are adjacent.
 
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Thank you for all your help, combined with my questions to the professor and the knowledge I found on the internet, I successfully completed my task of building a one-bit full adder in the lab. Tons of wires running around everywhere, but I got it done.
Thanks again.
 
Well done. That's quite a complex "first circuit" to build. I think mine was a lot simpler.
 

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