Question 1
The amount of ROM needed to implement a 4 bit multiplier is
64 bits
128 bits
1 Kbits
2 Kbits
Question 2
A computer has a 256 KByte, 4-way set associative, write back data cache with block size of 32 Bytes. The processor sends 32 bit addresses to the cache controller. Each cache tag directory entry contains, in addition to address tag, 2 valid bits, 1 modified bit and 1 replacement bit. The number of bits in the tag field of an address is
11
14
16
27
Question 3
Register renaming is done in pipelined processors
as an alternative to register allocation at compile time
for efficient access to function parameters and local variables
to handle certain kinds of hazards
as part of address translation
Question 4
Consider the data given in previous question. The size of the cache tag directory is
160 Kbits
136 bits
40 Kbits
32 bits
Question 5
Which of the following DMA transfer modes and interrupt handling mechanisms will enable the highest I/O band-width?
Transparent DMA and Polling interrupts
Cycle-stealing and Vectored interrupts
Block transfer and Vectored interrupts
Block transfer and Polling interrupts
Question 6
In a k-way set associative cache, the cache is divided into v sets, each of which consists of k lines. The lines of a set are placed in sequence one after another. The lines in set s are sequenced before the lines in set (s+1). The main memory blocks are numbered 0 onwards. The main memory block numbered j must be mapped to any one of the cache lines from.
(j mod v) * k to (j mod v) * k + (k-1)
(j mod v) to (j mod v) + (k-1)
(j mod k) to (j mod k) + (v-1)
(j mod k) * v to (j mod k) * v + (v-1)
Question 7
Consider the following sequence of micro-operations.
MBR ← PC
MAR ← X
PC ← Y
Memory ← MBR
Which one of the following is a possible operation performed by this sequence?
Instruction fetch
Operand fetch
Conditional branch
Initiation of interrupt service
Question 8
Consider an instruction pipeline with five stages without any branch prediction: Fetch Instruction (FI), Decode Instruction (DI), Fetch Operand (FO), Execute Instruction (EI) and Write Operand (WO). The stage delays for FI, DI, FO, EI and WO are 5 ns, 7 ns, 10 ns, 8 ns and 6 ns, respectively. There are intermediate storage buffers after each stage and the delay of each buffer is 1 ns. A program consisting of 12 instructions I1, I2, I3, …, I12 is executed in this pipelined processor. Instruction I4 is the only branch instruction and its branch target is I9. If the branch is taken during the execution of this program, the time (in ns) needed to complete the program is
132
165
176
328
Question 9
A RAM chip has a capacity of 1024 words of 8 bits each (1K × 8). The number of 2 × 4 decoders with enable line needed to construct a 16K × 16 RAM from 1K × 8 RAM is
4
5
6
7
Question 10
The following code segment is executed on a processor which allows only register operands in its instructions. Each instruction can have atmost two source operands and one destination operand. Assume that all variables are dead after this code segment.
c = a + b;
d = c * a;
e = c + a;
x = c * c;
if (x > a) {
y = a * a;
}
else {
d = d * d;
e = e * e;
}
Suppose the instruction set architecture of the processor has only two registers. The only allowed compiler optimization is code motion, which moves statements from one place to another while preserving correctness. What is the minimum number of spills to memory in the compiled code?
0
1
2
3
There are 241 questions to complete.