How does CPU interact with Memory, What all System call being generates during interaction?

Question

I have few questions about Cache Memory

1) My understanding of cache memory is, there are 3 type of cache memory,
1. Within RAM
2. Within CPU (L1,L2,L3)
3. Separate Hardware which is costlier than all others.

Please correct if I am wrong,

2) Who stores the data into cache? I mean, can we write a program which should use only cache memory? If yes then how to do it? if no then who manages that?
For example,
Cache memory within RAM, is it managed by Kernel?(Memory Management Unit)
Cache memory within CPU, is it managed by CPU itself?

3) Why cache memory is faster than RAM?

Answer 1

RAM works in conjunction with the central processing unit (CPU). If RAM is the temporary memory, you can think of the CPU as the brain of the computer. The CPU chip retrieves data from the RAM. The chip takes those instructions and begins to move and process data through the motherboard in the correct order to its next designated location. The CPU runs the computer the same way the human brain performs certain tasks that affect your senses, emotions and abilities to physically move and speak. Without the CPU, your computer will not be able to perform any of the functions it's designed for to keep your computer running efficiently.

For More Details of System Call, Buses Please follow the below link: http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm