I was watching a lecture and got confused at one point when professor said that to distinguish between two addresses having same values of offset as well as index bit we need tag.Why we need tag ? for example He was explaining that both addresses can have different values .I want to know that how can value be different when we know offset and index both as it refers to exact byte location of whole word array ? isn't it ? please check the fallowing video at 3:25 .thanks .http://youtu.be/WW-_i8LmgvE?t=3m25s
Why we need tagbits when we already have indexbit and offset?
memory management;cpu cache;virtual memory