Our Aim is to crate the RAM of 4M * 32
It actually represent that we should create the RAM having 4M entries each of 32 bits .
Now to construct this we have building block of 512 K * 8 that is .. we have 512 K words each of 8 bits ...
But as per requirement we should have 32 bits in one words so to have 32 bits we need 32/8 = 4
So one row needs 4 chips of 512K * 8 bits , so that we will have 512 K * 32 bits ..
So number of rows required = 4M * 32/ 512 K * 32 = 8 ROWS we need
As one row have 4 chips .. 8 rows will have 32 chips .
SO 32 CHIPS ARE NEEDED TO CREATE RAM OF 4M * 32 bits .