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45 lines
1.0 KiB
Markdown
45 lines
1.0 KiB
Markdown
---
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title: "02-combinatorial-logic"
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aliases:
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tags:
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- cosc204
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- lecture
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sr-due: 2022-07-19
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sr-interval: 3
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sr-ease: 250
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---
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- [slides](https://blackboard.otago.ac.nz/bbcswebdav/pid-2954102-dt-content-rid-18888626_1/courses/COSC204_S2DNI_2022/L2%20-%20Combinatorial%20Logic.pdf)
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# Combinatorial Logic Circuit
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> [!Definition]
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> Combinatorial Logic Circuit is a circuit whose digital outputs are dependent only on its digital inputs
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They can be described using logic expressions and therefore logic gates. We assume the outputs respond immediately^[1]
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They can be defined:
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- Using a truth table
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- Using boolean equations ($Q\ =\ A+\ B$)
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- Using graphical symbols
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- [1 Bit half adder(https://i.imgur.com/mjCVU4I.png)
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- 1 Bit full adder: (includes carry input) [](https://i.imgur.com/yu6kS83.png)
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# Circuit basics:
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- current flows + to -
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- input to a unit (e.g., LED) is the + end
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# Logic Gates
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- NOT
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- AND
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- OR
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- NAND
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- NOR
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- XOR/EOR
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[^1] : In real circuits propagation delay must be considered, hence the clock cycle on CPUs
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