Digital Circuits - Online Test
Q1. 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?
Answer : Option C
Explaination / Solution:
In push operation 3 cycles involved: 6T+3T+3T = 127
POP operation 3 cycle involved: 4T+3T+3T = 107
So in the opcode fetch cycle 2T states are extra in case of push compared to POP and this is needed to decrement the SP.
Q2. The DFT of a vector [a b c d] is the vector [α β γ δ]. Consider the product 
The DFT of the vector [p q r s] is a scaled version of
Answer : Option A
Explaination / Solution:
No Explaination.
Q3. In the circuit shown below, Q1 has negligible collector-to-emitter saturation voltage and the diode drops negligible voltage across it under forward bias. If Vcc is +5 V, X and Y are digital signals with 0 V as logic 0 and Vcc as logic 1,
then the Boolean expression for Z is
Answer : Option B
Explaination / Solution:
No Explaination.
Q4. There are four chips each of 1024 bytes connected to a 16 bit address bus as
shown in the figure below, RAMs 1, 2, 3 and 4 respectively are mappped to
addresses
Answer : Option D
Explaination / Solution:
No Explaination.
