GATE EC Digital Circuits questions

The following FIVE instructions were executed on an $8085$ microprocessor. MVI A, $33$H MVI B, $78$H ADD B CMA ANI $32$H The Accumulator value immediately after the execution of the fifth instruction is

A finite state machine (FSM) is implemented using the D flip-flop A and B, and logic gates, as shown in the figure below. The four possible states of the FSM are $Q_{A}Q_{B}=00,01,10$ and $11$. Assume that $X_{IN}$ is held at a constant logic level throughout the operation of the FSM. When the FSM is initialized to the state $Q_{A}Q_{B}=00$ and …

For the circuit shown in the figure, P and Q are the inputs and Y is the output. The logic implemented by the circuit is

Consider the circuit shown in the figure. The Boolean expression $F$ implemented by the circuit is

In a DRAM,

The state diagram of a finite state machine (FSM) designed to detect an overlapping sequence of three bits is shown in the figure. The FSM has an input 'In' and an output 'Out'. The initial state of the FSM is $S_0$. If the input sequence is $10101101001101$, starting with the left-most bit, then the number of times 'Out' will be $1$ is ____________

Figure Ⅰ shows a $4$-bit ripple carry adder realized using full adders and Figure Ⅱ shows the circuit of a full-adder (FA). The propagation delay of the XOR, AND and OR gates in Figure Ⅱ are $20$ ns, $15$ ns and $10$ ns, respectively. Assume all the inputs to the $4$-bit adder are initially reset to $0$. Figure I Figure II At $t = 0$, the …

A programmable logic array (PLA) is shown in the figure. The Boolean function $F$ implemented is

A small percentage of impurity is added to an intrinsic semiconductor at $300 \: K$. Which one of the following statements is true for the energy band diagram shown in the following figure?

Consider the following statements for a metal oxide semiconductor field effect transistor (MOSFET): Which of the above statements are INCORRECT? P and Q P and S Q and R R and S

The functionality implemented by the circuit below is

In an $8085$ system, a PUSH operation requires more clock cycles than a POP operation. Which one of the following options is the correct reason for this?

Assume that all the digital gates in the circuit shown in the figure are ideal, the resistor $R=10\Omega$ and the supply voltage is $5\:V$. The $D$ flip-flops $D_{1} \:, D_{2} \:, D_{3} \:, D_{4}$ and $D_{5}$ are initialized with logic values $0,1,0,1$ and $0$, respectively. The clocks has a $30\%$ duty cycle. The average power dissipated (in …

A $4:1$ multiplexer is to be used for generating the output carry of a full adder. $A$ and $B$ are the bits to be added while $C_{in}$ is the input carry and $C_{out}$ is the output carry. $A$ and $B$ are to be used as the select bits with $A$ being the more significant select bit. Which one of the following statements correctly describes the …

An $8$ Kbyte ROM with an active low Chip Select input $\left (\overline{CS}\right )$ is to be used in an $8085$ microprocessor based system. The ROM should occupy the address range $1000H$ to $2FFFH$. The address lines are designated as $A_{15}$ to $A_{0}$, where $A_{15}$ is the most significant address bit. Which one of the following logic …

In an $N$ bit flash ADC, the analog voltage is fed simultaneously to $2^{N}-1$ comparators. The output of the comparators is then encoded to a binary format using digital circuits. Assume that the analog voltage source $V_{in}$ (whose output is being converted to digital format) has a source resistance of $75 \: \Omega$ as shown in the circuit …

The state transition diagram for a finite state machine with states $A$, $B$ and $C$, and binary inputs $X$, $Y$ and $Z$, is shown in the figure. Which one of the following statements is correct?

The $I-V$ characteristics of three types of diodes at the room temperature, made of semiconductors $X, Y$ and $Z$, are shown in the figure. Assume that the diodes are uniformly doped and identical in all respects except their materials. If $E_{gX}$,$E_{gY}$ and $E_{gZ}$ are the band gaps of $X, Y$ and $Z$, respectively, then

In an $8085$ microprocessor, the contents of the accumulator and the carry flag are $A7$ (in hex) and $0$, respectively. If the instruction $RLC$ is executed, then the contents of the accumulator (in hex) and the carry flag, respectively, will be

The logic functionality realized by the circuit shown below is