25 lines
776 B
Plaintext
25 lines
776 B
Plaintext
// This file is part of www.nand2tetris.org
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// and the book "The Elements of Computing Systems"
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// by Nisan and Schocken, MIT Press.
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// File name: projects/demo/Xor.hdl
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/**
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* Exclusive-or gate: true if either a is true and b is false, or
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* a is false and b is true; false otherwise.
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* QUESTION: how can the simulator execute this program properly without
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* HDL implementations of the underlying Not, And, and Or chip-parts?
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* Answer: since the demo folder contains no Not.hdl, And.hdl and Or.hdl
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* files, the simulator reverts to using their built-in implementations.
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*/
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CHIP Xor {
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IN a, b;
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OUT out;
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PARTS:
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Not (in=a, out=nota);
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Not (in=b, out=notb);
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And (a=a, b=notb, out=x);
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And (a=nota, b=b, out=y);
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Or (a=x, b=y, out=out);
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} |