Show how to build a S-R type latch using a single 74HC74 positive-edge triggered
ID: 1937944 • Letter: S
Question
Show how to build a S-R type latch using a single 74HC74 positive-edge triggered D-type flip-flop and no other components. A logic symbol for a 74HC74 D-type flip-flop is shown below. Analyze the circuit shown below. It consists of three (3) D-type flip-flops and a 2-input XOR gate. Representative LOAD and CLK signals are shown below the circuit diagram. Q2, Q1, and Q0 are the outputs. The person constructing the circuit above makes a wiring mistake. The PRESET inputs (PR) are accidentally all tied to VDD and the CLEAR inputs (CLR) are accidentally all tied to the LOAD signal. Analyze the circuit. Analyze the circuit shown below. It consists of three (3) D-type flip-flops and a 2-input XOR gate. Representative LOAD and CLK signals are shown below the circuit diagram. Q2, Q1, and Q0 are the outputs. The person constructing the circuit above makes a wiring mistake. The PRESET inputs (PR) are accidentally all tied to VDD and the CLEAR inputs (CLR) are accidentally all tied to the LOAD signal. Analyze the circuit. Discuss your results taking into the account the operation of the circuit in Question 2).Explanation / Answer
1.the characteristic equation of SR is Qn+1 = S + R'Qn and D FlipFlop is Qn+1=D so connect D= S + R' Qn 2.it is a mod 7 counter it initially loads to 100 and passes through the states 100,010,101,110,111,011,001,100 repeats