very simple question PIC16F84

[arod]

I am reading this book describing the operation of the memory banks and it states:

"Locations 0Ch - 4Fh are general purpose registers (GPR) which are used as RAM memory. When locations 8Ch - CFh in Bank 1 are accessed, we actually access the exact same locations in Bank 0. In other words , whenever you wish to access one of the GPR registers, there is no need to worry about which bank we are in!"

I am a bit confused as to why it doesn't make a difference what bank you select. If for instance I store data in 4F, will the same data in 4F be in CF? The answer is probably obvious, but I cannot seem to grasp it.

edit: I think I answered my own question lol, but why does it do that anyways. It seems like a waste of space.

 

[szabi]

The 8Ch - CFh area isn't actually implemented, there is no RAM in reality there. So nothing is wasted.

 

[atferrari]

Common bank

No a waste at all! There is an advantage and a great one.

It doen's matter what bank is actuallys elected; those registers in that area may be used without changing the bank.