Question

Which of the following is used to determine, if a piece of data in cache needs to be written back to cache ?

A. Dirty Bit=1

B.Valid Bit=0

B Dirty Bit=0

D.Valid Bit=1

Answer 1

Cache:  The memory that stores data so that future requests can be served faster is called the cache memory. The data stored in a cache might be the result of a computation or a copy of data.

Dirty bit: A dirty bit also referred to as a modified bit is associated with computer memory and indicates whether the corresponding block of memory has been modified.

The dirty bit is set to 1 when the processor writes data to this memory. The bit also indicates the associated block of memory that has been modified and has not been saved to storage yet.

Hence, if a piece of data in cache needs to be written back to cache the dirty bit has to be set 0.

Dirty bit=0 is the answer.