Given: A MIPS-based computer system with 2 GB of main memory that is built on a

Question

Given: A MIPS-based computer system with 2 GB of main memory that is built on a single circuit board. It is designed with a single control signal between the CPU chip and main memory, i.e. one bit of control that is set to one for Read operations and zero for Write operations. 4 banks memory interleaved is used.

1) How long does it takes to fetch 8 words from the memory to MIPS registers? Assume that one cycle is required to place the address and one cycle to transfer one word and 15 cycles for memory access.

Explanation / Answer

Coming to the concept of time taken by the system to access the data, read the data and write it back to the system, we need to consider all the required parameters such as, the time required to read a block of word, to write the block of word and the interleaving used.

The interleaving is used to minimise the read and write access. In this process the memory is divided into the individually different chunks to process out the operation of its own word.

According to the problem given, we assume that each read and write operation takes one cycle. And in addition we have used 4 banks of memory for interleaving.

Initially, without interleaving, time required was (1+1+15) =17 cycles/word.

i.e One cycle to place the address, one cycle to transfer one word and 15 cycles for memory access.

Now, y the concept of interelaving the time required would be:-

1 + 15 + 2 x (4 x 1) = 24 cycles.

As per the question asked, 4 banks of memory interleaving is used, and altogether we hav to transfer 8 word of data, therefore the formula has been modified above.

Thus, the total time required to fetch 8 words would be 24 cycles.

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.