Log In

Web Page

Machine instructions and Addressing modes. ALU, data‐path and control unit. Instruction pipelining. Memory hierarchy: cache, main memory and secondary storage; I/O interface (Interrupt and DMA mode)

$$\small{\overset{{\large{\textbf{Mark Distribution in Previous GATE}}}}{\begin{array}{|c|c|c|c|c|c|c|c|}\hline
\\\hline\textbf{1 Mark Count}&2&2&2&0&1&1&0&1.3&2
\\\hline\textbf{2 Marks Count}&1&3&4&3&2&5&1&3&5
\\\hline\textbf{Total Marks}&4&8&10&6&5&11&\bf{4}&\bf{7.3}&\bf{11}\\\hline

Hot questions in CO and Architecture

98 votes
14 answers
Consider a system with a two-level paging scheme in which a regular memory access takes $150$ $nanoseconds$, and servicing a page fault takes $8$ $milliseconds$. An average instruction takes $100$ nanoseconds of CPU time, and two memory accesses. The TLB ... average instruction execution time? $\text{645 nanoseconds}$ $\text{1050 nanoseconds}$ $\text{1215 nanoseconds}$ $\text{1230 nanoseconds}$
asked Sep 5, 2014 in CO and Architecture gatecse 28.3k views
74 votes
8 answers
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 ... is taken during the execution of this program, the time (in ns) needed to complete the program is $132$ $165$ $176$ $328$
asked Sep 6, 2014 in CO and Architecture Kriss Singh 19.9k views
101 votes
4 answers
A $5$ stage pipelined CPU has the following sequence of stages: IF - instruction fetch from instruction memory RD - Instruction decode and register read EX - Execute: ALU operation for data and address computation MA - Data memory access - for write access, the register read ... clock cycles taken to complete the above sequence of instructions starting from the fetch of $I_1$? $8$ $10$ $12$ $15$
asked Sep 22, 2014 in CO and Architecture Kathleen 20.7k views
45 votes
9 answers
Consider a disk drive with the following specifications: $16$ surfaces, $512$ tracks/surface, $512$ sectors/track, $1$ KB/sector, rotation speed $3000$ rpm. The disk is operated in cycle stealing mode whereby whenever one $4$ byte word is ready it is sent to memory; similarly, ... is $40$ nsec. The maximum percentage of time that the CPU gets blocked during DMA operation is: $10$ $25$ $40$ $50$
asked Sep 22, 2014 in CO and Architecture Kathleen 17.8k views
61 votes
6 answers
Consider a $2-$way set associative cache with $256$ blocks and uses $LRU$ replacement. Initially the cache is empty. Conflict misses are those misses which occur due to the contention of multiple blocks for the same cache set. Compulsory misses occur due to first time access ... $10$ times. The number of conflict misses experienced by the cache is _________ .
asked Feb 14, 2017 in CO and Architecture Arjun 16.5k views
48 votes
5 answers
Consider the following reservation table for a pipeline having three stages $S_1, S_2 \text{ and } S_3$. $\begin{array}{|ccccc|} \hline \textbf{Time} \rightarrow \\\hline & \text{1}& \text{2} & \text{$3$} & \text{$4$} & \text{$5$} \\\hline \textbf{$S _1$} & \text{$ ... $}\\\hline \textbf{$S _3$} & & & \text{$X$} & \\\hline \end{array}$ The minimum average latency (MAL) is ______
asked Feb 16, 2015 in CO and Architecture jothee 16.8k views
69 votes
6 answers
Consider a three word machine instruction $ADD A[R_0], @B$ The first operand (destination) $A[R_0]$ uses indexed addressing mode with $R_0$ as the index register. The second operand (source) [email protected]$ uses indirect addressing mode. $A$ and $B$ are memory addresses ... destination (first operand). The number of memory cycles needed during the execution cycle of the instruction is: $3$ $4$ $5$ $6$
asked Sep 22, 2014 in CO and Architecture Kathleen 15.3k views
56 votes
8 answers
The stage delays in a $4$-stage pipeline are $800, 500, 400$ and $300$ picoseconds. The first stage (with delay $800$ picoseconds) is replaced with a functionality equivalent design involving two stages with respective delays $600$ and $350$ picoseconds. The throughput increase of the pipeline is ___________ percent.
asked Feb 12, 2016 in CO and Architecture Sandeep Singh 11.5k views
35 votes
5 answers
Consider a system with $2$ level cache. Access times of Level $1$ cache, Level $2$ cache and main memory are $1$ $ns$, $10$ $ns$, and $500$ $ns$ respectively. The hit rates of Level $1$ and Level $2$ caches are $0.8$ and $0.9$, respectively. What is the average access time of the system ignoring the search time within the cache? $13.0$ $12.8$ $12.6$ $12.4$
asked Nov 2, 2014 in CO and Architecture Ishrat Jahan 15.5k views
62 votes
10 answers
Consider a machine with a byte addressable main memory of $2^{16}$ bytes. Assume that a direct mapped data cache consisting of $32$ lines of $64$ $bytes$ each is used in the system. A $50$ x $50$ two-dimensional array of bytes is stored in the main memory starting from ... of the data cache do not change in between the two accesses. How many data misses will occur in total? $48$ $50$ $56$ $59$
asked Sep 22, 2014 in CO and Architecture Kathleen 12.3k views
66 votes
9 answers
Consider a two-level cache hierarchy with $L1$ and $L2$ caches. An application incurs $1.4$ memory accesses per instruction on average. For this application, the miss rate of $L1$ cache is $0.1$; the $L2$ cache experiences, on average, $7$ misses per $1000$ instructions. The miss rate of $L2$ expressed correct to two decimal places is ________.
asked Feb 14, 2017 in CO and Architecture Arjun 10.5k views
76 votes
10 answers
Suppose the functions $F$ and $G$ can be computed in $5$ and $3$ nanoseconds by functional units $U_{F}$ and $U_{G}$, respectively. Given two instances of $U_{F}$ and two instances of $U_{G}$, it is required to implement the computation $F(G(X_{i}))$ for $1 \leq i \leq 10$. Ignoring all other delays, the minimum time required to complete this computation is ____________ nanoseconds.
asked Feb 12, 2016 in CO and Architecture Akash Kanase 10.4k views
42 votes
5 answers
A processor has $16$ integer registers $(R0, R1, \ldots , R15)$ and $64$ floating point registers $(F0, F1, \ldots , F63).$ It uses a $2- byte$ instruction format. There are four categories of instructions: $Type-1, Type-2, Type-3,$ and $Type-4.$ $Type-1$ ... $Type-4$ category consists of $N$ instructions, each with a floating point register operand $(1F).$ The maximum value of $N$ is _____
asked Feb 14, 2018 in CO and Architecture gatecse 10.3k views
56 votes
5 answers
A computer system has an $L1$ cache, an $L2$ cache, and a main memory unit connected as shown below. The block size in $L1$ cache is $4$ words. The block size in $L2$ cache is $16$ words. The memory access times are $2 \hspace{0.1cm} nanoseconds$ ... this transfer? $2 \hspace{0.1cm} nanoseconds$ $20 \hspace{0.1cm} nanoseconds$ $22 \hspace{0.1cm}nanoseconds$ $88 \hspace{0.1cm} nanoseconds$
asked Sep 30, 2014 in CO and Architecture jothee 16.3k views
42 votes
3 answers
In a two-level cache system, the access times of $L_1$ and $L_2$ caches are $1$ and $8$ clock cycles, respectively. The miss penalty from the $L_2$ cache to main memory is $18$ clock cycles. The miss rate of $L_1$ cache is twice that of $L_2$. The average memory access time (AMAT) of ... and $L_2$ respectively are $0.111$ and $0.056$ $0.056$ and $0.111$ $0.0892$ and $0.1784$ $0.1784$ and $0.0892$
asked Feb 14, 2017 in CO and Architecture Arjun 12.3k views
16 votes
3 answers
I want to clearly understand the difference between compulsory miss, conflict miss and capacity miss what I understood is compulsory miss: when a block of main memory is trying to occupy fresh empty line of cache, it is called compulsory miss conflict miss: when ... set-associative cache. Because in associative mapping, no block of main memory tries to occupy already filled line. is this correct?
asked Sep 22, 2016 in CO and Architecture Anusha Motamarri 11.9k views
77 votes
6 answers
An access sequence of cache block addresses is of length $N$ and contains n unique block addresses. The number of unique block addresses between two consecutive accesses to the same block address is bounded above by $k$. What is the miss ratio if the access sequence is passed through a cache of ... $\left(\dfrac{1}{N}\right)$ $\left(\dfrac{1}{A}\right)$ $\left(\dfrac{k}{n}\right)$
asked Sep 28, 2014 in CO and Architecture jothee 10.1k views
34 votes
6 answers
The instruction pipeline of a RISC processor has the following stages: Instruction Fetch $(IF)$, Instruction Decode $(ID)$, Operand Fetch $(OF)$, Perform Operation $(PO)$ and Writeback $(WB)$, The $IF$, $ID$, $OF$ and $WB$ stages take $1$ ... there are no data hazards and no control hazards. The number of clock cycles required for completion of execution of the sequence of instruction is _____.
asked Feb 14, 2018 in CO and Architecture gatecse 9.3k views
42 votes
10 answers
A cache memory unit with capacity of $N$ words and block size of $B$ words is to be designed. If it is designed as a direct mapped cache, the length of the TAG field is 10 bits. If the cache unit is now designed as a 16-way set-associative cache, the length of the TAG field is ____________ bits.
asked Feb 14, 2017 in CO and Architecture Arjun 10.3k views