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Truth Table. NOT AND NAND OR NOR XOR XNOR. Generate a Truth Table. NAND Based Logic Gates. Multiple Inputs Logic Gates. NOR Based Logic Gates. Sum of Products. A “sum of products” implementation outputs a 1 when one of the intermediates products is true. Home Alarm Logic.
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Truth Table • NOT • AND • NAND • OR • NOR • XOR • XNOR
Sum of Products • A “sum of products” implementation outputs a 1 when one of the intermediates products is true
Sum of Products Equation • Parts • 12 inverters • 3 2-input AND gates for each 4-input AND gate. Therefore, 24 2-input AND gates. • 7 2-input OR gates.
Delay Calculations • Parts • 12 inverters (1 TTL delay) • 3 2-input AND gates for each 4-input AND gate. Therefore, 24 2-input AND gates. • Each AND gate: 2 TTL delay • For each 4-input ANDN gate: 4 TTL delay • 7 2-input OR gates. • 2 TTL delay for each OR gate • 7 2-input OR gates (6 TTL delay) • Total delay: 6 TTL delay+4 TTL delay+1 TTL delay=11 TTL delay
Looping • Groups of Two • Groups of Four • Group of Eight
OR Identities (2) • ) (
DeMorgan’s NOR Theorm • Invert each input • Swap an AND with an OR, and an OR with an AND.
DeMorgan’s NAND Theorm • Invert each input • Swap an AND with an OR, and an OR with an AND.
Factoring—the first & third terms above haveACin common, which can be factored out: Since B + B = 1, then… z = A(C + B) Solution