A micro programmed control unit

Is useful when small programs are to be run

Is faster than a hardwired unit

Facilitates easy implementation of a new instruction

Is useful when small programs are to be run

Program counter contents indicate:

The time needed to execute a program.

The time elapsed since execution begins.

The count of programs being executed after switching the power ON

The address where next instruction is stored.

The time needed to execute a program.

1.	A stack organised computer is characterised by instructions with
A.	Indirect addressing
B.	direct addressing
C.	zero addressing
D.	index addressing
Answer» D. index addressing

2.	Consider a 32-bit processor which supports 70 instructions. Each instruction is 32 bit long and has 4 fields namely opcode, two register identifiers and an immediate operand of unsigned integer type. Maximum value of the immediate operand that can be supported by the processor is 8191. How many registers the processor has?
A.	32
B.	64
C.	128
D.	16
Answer» C. 128

3.	A CPU has 12 registers and uses 6 addressing modes. RAM is 64K × 32. What is the maximum size of the op-code field if the instruction has a register operand and a memory address operand?
A.	8 bits
B.	9 bits
C.	10 bits
D.	11 bits
Answer» C. 10 bits

4.	Consider a processor with byte - addressable memory. Assume that all registers, including Program Counter (PC) and Program Status Word (PSW), are of size 2 bytes. A stack in the main memory is implemented from memory location (0100)16 and it grows upward. The stack pointer (SP) points to the top element of the stack. The current value of SP is (016E)16. The CALL instruction is of two words, the first word is the op - code and the second word is the starting address of the subroutine (one word = 2 bytes). The CALL instruction is implemented as follows:• Store the current value of PC in the stack• Store the value of PSW register in the stack• Load the starting address of the subroutine in PCThe content of PC just before the fetch of a CALL instruction is (5FA0)16. After execution of the CALL instruction, the value of the stack pointer is
A.	(016A)16
B.	(016C)16
C.	(0170)16
D.	(0172)16
Answer» E.

5.	A micro programmed control unit
A.	Is faster than a hardwired unit
B.	Facilitates easy implementation of a new instruction
C.	Is useful when small programs are to be run
D.	All of the above
Answer» C. Is useful when small programs are to be run

6.	A byte addressable computer has a memory capacity of 2m KB (Kbytes) and can perform 2n operations. An instruction involving 3 operands and one operator needs maximum of
A.	3m bits
B.	3m + n bits
C.	m + n bits
D.	none of the above
Answer» E.

7.	In the architecture of 8085 microprocessor match the following:A. Processing unitI. InterrruptB. Instruction unitII. General purpose RegisterC. Storage and Interface unitIII. ALU IV. Timing and ControlCode:
A.	A - IV, B - I, C - II
B.	A - III, B - IV, C - II
C.	A - II, B - III, C - I
D.	A - I, B - II, C - IV
Answer» C. A - II, B - III, C - I

8.	A computer which issues instructions in order, has only 2 registers and 3 opcodes ADD, SUB and MOV. Consider 2 different implementations of the following basic block:Case 1 Case 2t1 = a + b; t2 = c + d;t2 = c + d; t3 = e – t2;t3 = e – t2; t1 = a + b;t4 = t1 – t2; t4 = t1 – t2; Assume that all operands are initially in memory. Final value of computation also has to reside in memory. Which one is better in terms of memory and by how many MOV instructions?
A.	Case 2, 2
B.	Case 2, 3
C.	Case 1, 2
D.	Case 1, 3
Answer» E.

9.	Action implementing instructor’s meaning are actually carried out by____
A.	Instruction fetch
B.	Instruction decode
C.	Instruction execution
D.	Instruction program
Answer» D. Instruction program

10.	Program counter contents indicate:
A.	The time elapsed since execution begins.
B.	The count of programs being executed after switching the power ON
C.	The address where next instruction is stored.
D.	The time needed to execute a program.
Answer» D. The time needed to execute a program.

11.	Consider the following :1) Operation code2) Source operand reference3) Result operand reference4) Next instruction referenceWhich of the above are typical elements of machine instructions?
A.	1, 2 and 3 only
B.	1, 2 and 4 only
C.	3 and 4 only
D.	1, 2, 3 and 4
Answer» E.