Graded quiz 3
Question 1 In n=4, what set(s) of cube(s) is(are) equivalent to the set {0001, 0011, 0100, 0101, 1010, 1011, 1100, 1110}? (equivalent= they cover the same set of minterms)
00x1, 010x, x1x0, 101x
Question 1 In n=3, which set(s) of cube(s) is(are) equivalent to the set (000, 001, 011, 10x)? (equivalent= they cover the same set of minterms)
x00, x01, 0x1
Question 2 Design a circuit to compare two 2-bit numbers A and B (A = a1 a0; B = b1 b0). The circuit has three outputs G (greater than), E (equal to) and L (less than) so that: G = 1 if A > B, E = 1 if A = B, and L = 1 if A < B. Note: Inputs to the circuit must be named as a1, a0, b1, b0, G, E and L. Respect upper and lower cases. Instructions to answer this question 1) In the virtual machine, open VerilUOC_Desktop and draw the circuit. 2) Click in “Simulate”->”Verification” and then click in the VerilCirc tab. 3) In "Module" select "Graded Exercises" and click on exercise 3.2.a. 4) VerilCirc returns a 4 uppercase letters code. Type it in the answer box.
YTZE
Question 3 Design a digital circuit that receives a 4 bits BCD-coded(*) number X = abcd and returns a signal M7=1 if X ≥ 7, and M7=0 otherwise. The algorithm below shows the functional description of the circuit ("dc" means a “don’t care” combination). Inputs and outputs of the circuit must be named as: a, b, c, d, and M7. Respect the upper and lowercases. (*): BCD code (Binary Coded Decimal) encodes any base-10 number from 0 to 9 in base-2, using 4 bits. That is, 0 is coded by 0000, 1 by 0001, 2 by 0010 and so on until 9, which is encoded by 1001. Base-10 numbers higher than 9 require at least 2 digits and, consequently, they will never enter to the circuit. Not Fixed Instructions to answer this question 1) In the virtual machine, open VerilUOC_Desktop and draw the circuit. 2) Click in “Simulate”->”Verification” and then click in the VerilCirc tab. 3) In "Module" select "Graded Exercises" and click on exercise <Variable>>. 4) VerilCirc returns a 4 uppercase letters code. Type it in the answer box.
Variable: 3.3.aOWKC
YVOM
Question 4 Not Fixed Instructions to answer this question 1) In the virtual machine, open VerilUOC_Desktop and draw the circuit. 2) Click in “Simulate”->”Verification” and then click in the VerilCirc tab. 3) In "Module" select "Graded Exercises" and click on exercise <Variable>>. 4) VerilCirc returns a 4 uppercase letters code. Type it in the answer box.
Variable: 3.4.aWNCZ
GJDC
Question 5 The following circuit consists of 7 identical components with 2 inputs "a" and "b", and 2 outputs "c" and "d". The maximum propagation time from inputs "a" or "b" to outputs "c" or"d" is equal to 0.5 ns. Which is the maximum propagation time from any input to any output (in ns.)? Introduce the answer in nanoseconds, with 1 decimal digit. Examples: If the propagation time is 8.9 ns., introduce 8.9; if the propagation time is 6 ns., introduce 6.0
2.5
Question 6
Question 7 (This exercise and the next one refer to the same statement) Consider a system with three input signals x, y and max and one output signal z. All signals are binary encoded non-negative integers. System specification: if (x - y) belongs to the interval 0 ≤ x - y ≤ max, then z = x - y; if (x - y) > max, then z = max; if (x - y) < 0, then z = 0. Assume that a procedure difference(A, B, s, C) has been previously defined, where A, B and C are non-negative integers and s is a 1-bit number, so that it computes the difference A – B under the form A – B = (-1)s•C (s is the sign and C is the absolute value of the result). Which of the following algorithms properly describes the system?
difference(x, y, a, b); difference(max, b, c, d); if c = 1 then e <= max; else e <= b; end if; if a = 1 then z <= 0; else z <= e; end if;
Question 8 (Let's continue with the last question) Assume that a module implementing the procedure difference(A, B, s, C) exists. If x and y are 4-bit numbers, which of the following circuits implements the desired system?
