## Computer Architecture (Q and A)

Q1(2012): Define Register Transfer Language with example.

Answer: A register transfer language (RTL) is a notation used to describe the micro-operation transfers between registers. It is a symbolic expression of the micro-operation sequences among register and memory and are used to implement machine-language instructions.

Every statement in Register Transfer Language implies the availability  of hardware circuit which implements the microoperation.
e.g. The statement R2 ← R1 implies the existence of the necessary circuitry to implement the transfer from register (R1) to register (R2).

Q2(2013): Explain the working of cache memory.

Answer: Cache is a high speed memory placed between CPU and main memory to speed up access of data and instructions stored in main memory.

The access time of cache memory is much less (i.e. 80 nano seconds) when compared to main memory access. Cache is not accessible to user. It increases the operating speed of CPU by minimizing its wait cycles while fetching instructions and data from main memory.

The capacity of cache memory is less than that of main memory. Cache memory works under different configurations i.e.

• Direct Mapping
• Fully Associative
• Set Associative

Q3: A computer uses RAM chip of 1024 x 1 capacity. How many chips are needed for providing a capacity of 1024 bytes.

Answer: Capacity = 1024 x 1
= 1024 words and each word of 1 bit.
1 bytes  = 8 bytes
1024 bytes   = 1024 x 8 bits

Number of chips required for 1024 bytes = (1024 x 8) ÷(1024 x 1) = 8 chips

Q4(2013): Determine the number of clock cycles that it takes to process 200 tasks in a six-segment pipeline.

Answer: Number of segments (k) = 6
No. of tasks to be processed (n) = 200
Number of clock cycles = k + n -1 = 6 + 200 - 1 = 205 clock cycles.