RAKESH, the purpose of his discussion forum is not to provide you with
source code for a specific problem. Developing code for an application
may be a task of hours and days, and this is nothing you should expect
from the people here. If there is any reference source code available,
you should find it somewhere across the internet, otherwise you have to
implement it by yourself using the information from the data sheet.
Writing a flash protocol is quite straight forward.
We can help to solving a specific problem regarding VHDL and FPGA, but
forum participants will usually get a bit angry if you ask them to do
your homework. Please keep this in mind. Whenever you have a problem
with understanding or any question about a piece of code that is not
working as expected, your posting will be welcome here.