Curs 3 - Bazele logice ale calculatoarelor - derivat
Curs 3 - Bazele logice ale calculatoarelor - derivat
Curs 3 - Bazele logice ale calculatoarelor - derivat
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f ( x,<br />
y,<br />
z)<br />
= x ⋅ y ⋅ z = x + y + z<br />
Poarta SI-NU (NAND) cu 4 intrari<br />
x<br />
y f<br />
z<br />
u<br />
f ( x,<br />
y,<br />
z,<br />
u)<br />
= x ⋅ y ⋅ z ⋅u<br />
= x + y + z + u<br />
Poarta SAU-EXCLUSIV (XOR) cu 2 intrari<br />
x f<br />
y<br />
f ( x,<br />
y)<br />
= x ⊕ y = x ⋅ y + x ⋅ y<br />
Portile <strong>logice</strong> se pot utiliza pentru implementarea de functii de<br />
comutatie si realizarea de scheme <strong>logice</strong> combination<strong>ale</strong>.<br />
Exemplu. Sa se implementeze cu porti <strong>logice</strong> functia de comutatie:<br />
f ( x,<br />
y,<br />
z)<br />
= x ⋅ y ⋅ z + x ⋅ y ⋅ z + x ⋅ y ⋅ z + x ⋅ y ⋅ z<br />
Functia nu poate fi simplificata ca suma de produse si deci va fi<br />
implementata chiar expresia de comutatie data (fig.3.2.2):<br />
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