Category Archives: Computer Organisation Theory

All important theory placed here!

Draw the logic diagram of a full adder. Create a 2-bit adder-subtractor circuit using the block diagram of the full adder 6m Jun2006

Draw the logic diagram of a full adder. Create a 2-bit adder-subtractor circuit using the block diagram of the full adder 6m Jun2006 A combinational circuit which performs addition of two bits is called a half adder, while the combinational circuit which performs arithmetic addition of three bits (the third bit is the previous carry bit)… Read More »

Explain the following: Parity bit, Floating point notation, Refresh rates in video controllers and an l/O channel 8m Jun2006

Explain the following with the help of an example or a diagram, whichever is appropriate:    8m jun2006 (i)                 Parity bit (ii)               Floating point notation (iii)             Refresh rates in video controllers (iv)             An l/O channel     Parity bit An error bit changes from 0 to 1 or 1 to 0. One of the simplest… Read More »

Simplify the following Boolean function in POS form using K-maps, also draw a logic diagram using only NAND gates 5m Dec2005

 Simplify the following boolean function in POS form using K-maps : F (A, B, C, D) = Σ (0, 2, 4, 5, 6, 8, 10, 13, 15) Also draw a logic diagram using only NAND gates.         5m Dec2005    K-Map for F is: Thus, the simplified equations for F (A, B, C, D) =… Read More »

Evaluate the effective address if addressing mode is Direct, Relative, Register indirect, Index with lndex register 6m Dec2005

An instruction is stored at location 500 with its address field at location 501. The address field has the value 300. A processor register R1 contains the number 100. Evaluate the effective address if the addressing mode of the instruction is   6m Dec2005                        … Read More »

Represent the following numbers in IEEE-754 floating point single precision number format: 4m Dec2005

Represent the following numbers in IEEE-754 floating point single precision number format:           4m Dec2005 (i)                 1011.1001 (ii)                -0.0011001   Single Precision   S stands for Sign (white color) E stands for Exponent (yellow color) N stands for Number (also called Mantissa or Significand) (green color)   0this Sign bit (1 bit) 1st to 8this Exponent… Read More »

Explain the micro-instruction encoding methods with the help of suitable diagrams 10m Dec2005

Explain the micro-instruction encoding methods with the help of suitable diagrams. If a machine has a very large number of instructions and registers, which of the two encoding methods is preferred? 10m Dec2005  The characteristics of highly encoded and unencoded micro-instructions:- Unencoded micro-instructions  One bit is needed for each control signal; therefore, the number of… Read More »

Find out the errors, if any, in the following 5m Dec2005

Find out the errors, if any, in the following, and               5m Dec2005 (i)                 CMP AX, BX No error since two register operand are allowed for comparison in the permutations shown below. (ii)               IDlV AX, CH IDIV works or allows one parameter only and it can either be register or memory only as shown below. corrected… Read More »

Design a decade counter using D-flipflop. Show all the steps involved 10m Dec2005

Design a decade counter using D-flipflop. Show all the steps involved 10m Dec2005  Decade counter A BCD counter follows a sequence of ten states and returns to 0 after the count of 9. These counters are also called decade counters. This type of counter is useful in display applications in which BCD is required for… Read More »

What is an interrupt? Explain each of the conditions under which an interrupt occurs 5m Dec2005

 What is an interrupt? Explain each of the conditions under which an interrupt occurs 5m Dec2005 Interrupt An interrupt is an external signal that occurs due to an exceptional event. It causes interruption in the execution of current program of CPU. An interrupt may be generated by a number of sources, which may beeither internal… Read More »

Explain the working of the instruction pipelining, with the help of a diagram 5m Dec2005

Explain the working of the instruction pipelining, with the help of a diagram 5m Dec2005  INSTRUCTION PIPELINING To extract better performance instruction execution can be done through instruction pipeline. The instruction pipelining involves decomposing of an instruction execution to a number of pipeline stages. Some of the common pipeline stages can be instruction fetch (IF),… Read More »