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طراحی مدارهای منطقی. دانشگاه آزاد اسلامی واحد پرند. نیمسال دوم 92-93. طراحی مدارهای منطقی. دانشگاه آزاد اسلامی واحد پرند. بهینه سازی مدارهای منطقی: جدول کارنو. Optimization. Algebraic procedures problems The procedures are difficult to apply in a systematic way
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طراحی مدارهای منطقی دانشگاه آزاد اسلامی واحد پرند نیمسال دوم 92-93
طراحی مدارهای منطقی دانشگاه آزاد اسلامی واحد پرند بهینه سازی مدارهای منطقی: جدول کارنو
Optimization • Algebraic procedures problems • The procedures are difficult to apply in a systematic way • It is difficult to tell when you have arrived at a minimum solution • Karnaugh map (For 3 and 4 variables) • Quine-McCluskey
Optimization • Costdirectly related to The number of gates & Gate inputs used
Optimization • Karnaugh • Minimum cost two-level circuits composed of AND and OR gates • SOP: a group of AND gates feeding a single OR gate • POS:a group of OR gates feeding a single AND gate • Minimum SOP/POS • has minimum number of terms (Minimum number of gates) • has minimum number of literals (minimum number of gate inputs)
Karnaugh Map • Karnaugh map of a function • Specifies the value of the function for every combination of values of the independent variables • Like Truth table • Terms near each other with one bit difference • Maximum terms in one group (2,4,8,… terms) • Minimum groups
Karnaugh Map (3-variable) • Provingboolean algebra equations Consensus theorem
Karnaugh Map (3-variable) • Minimized SOP Not unique
Karnaugh Map (4-variable) • With Don’t cares • Group X’s if they simplify the function
Karnaugh Map (4-variable) • POS extraction
Karnaugh Map (EPI) • Using PIs and EPIs • Implicant • Prime Implicant (PI) • Essential Prime Implicant (EPI)
Karnaugh Map (EPI) • In the process of finding PIs: • don’t-cares are treated just like 1’s • Note PI composed entirely of X’s can never be part of the minimum solution