CSE303 Logic Design II Laboratory 01 # Student ID Student Name Grade (10) 1 Instructor signature 2 3 4 5 Delivery Date -1 / 15 -
Experiment 01 (Half adder) Objectives In the first experiment, a half adder is implemented exclusively using AND/NAND or OR/NOR gates. Circuit diagrams This experiment is set up according to the circuit diagram shown below. Virtual instruments Set the instruments to 8 bits and the display to decimal (DEC). Experiment set-up -2 / 15 -
Virtual instruments Set the instruments to 8 bits and the display to decimal (DEC). Experiment set-up -3 / 15 -
Evaluation Enter into the table the responses you see at the output when various inputs are applied. Truth table: A B Sum (S) Carry(C) 0 0 0 1 1 0 1 1 From the truth table for the addition of two single-bit operands it can be seen that output S, the "Sum" output, is only ever "1" if no more than one operand has a value of "1". What logical operation has the same effect? Exclusive NOR, XNOR or equivalence Exclusive AND, XAND or equivalence Exclusive OR, XOR or antivalence A carry of C = 1 is output by the half-adder circuit when operand and operand B simultaneously have the value "1". What logical circuit has the same effect as this? NAND circuit OR circuit AND circuit Test of knowledge Use this table to determine the logic equation for a half adder. Logic equation for half-adder S (sum) output: S = (A B) (A B) S = (A B) + (A B) S = (A B) + (A B) Logic function for half adder C (carry) output: -4 / 15 -
C = A + B C = A B C = A B -5 / 15 -
Experiment 02 (Full adder) Experiment set-up -6 / 15 -
Evaluation Vary the logic level using the input switches at the input to the circuit in accordance with the truth table provided and determine the output responses whích are missing from the table. A B C Sum (S) Carry (c n+1 ) 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Karnaugh maps The Karnaugh-Veitch diagrams below show the contents of the truth table with separate entries for the sum and carry outputs. Sum output: A A B 0 1 0 1 B 1 0 1 0 C C C Carry output: A A B 1 1 1 0 B 0 1 0 0 C C C What range of numbers can be added together using a 1-bit full adder? -7 / 15 -
31 63 15 1 Test of knowledge Decimal numbers 6 and 16 are to be added together. How many 1-bit full adders need to be cascaded together to accomplish this? Only one Ten Four Five -8 / 15 -
Experiment 03 (4-bit numbers) Circuit diagram Experiment set-up Evaluation Decimal Binary 8 4 2 1-9 / 15 -
5 0 1 0 1 Inputs A-D 5 + 0 1 0 1 Inputs E-H Carry 10 Sum Decimal Binary 8 4 2 1 10 1 0 1 0 Inputs A-D 14 + 1 1 1 0 Inputs E-H Carry 24 Sum Do your calculated results agree with the actual results of the experiment? Yes No -10 / 15 -
Experiment 04 (Half subtractor) Circuit diagram Experiment set-up Evaluation Enter into the table the responses of the difference and carry/borrow-bit outputs when various logical inputs are applied. Truth table for half-subtractors): -11 / 15 -
A B Difference (D) 0 0 0 1 1 0 1 1 Logic equation for difference: D = (A B) + (A B) D = (A B) (A B) D = (A B) + (A B) Carry (C) Logic equation for borrow (carry): C = A B C = A B C = A B -12 / 15 -
Experiment 05 (Full subtractor) Circuit diagram -13 / 15 -
Experiment set-up Evaluation Fill out the truth table provided by entering the responses of the full subtractor circuit. Truth table: A B C Difference (D) Carry (c n+1 ) 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Logic equation for difference: -14 / 15 -
D = (A B C) + (A B C) + (A B C) (A B C) D = (A B C) + (A B C) + (A B C) + (A B C) D = (A B C) + (A B C) + (A B C) + (A B C) Logic equation for borrow (carry): C n+1 = (A C) + (B C) + (A B) C n+1 = (A C) + (B C) + (A B) C n+1 = (A C) (B C) (A B) -15 / 15 -