ABSTRACT
This chapter examines what happens inside the core and during the memory transfers from the CPU to the main memory. In the early 1970s, INTEL designed a programmable chip in the beginning days of the concept of a "microprocessor", or "CPU", a digital device that can execute a program stored in memory. INTEL designed the 4004 processor to have 12 address bits, capable of addressing 4096 Bytes. INTEL designed support chips, such as an I/O controller and memory controller to allow their customers to interface the 4004 CPU to the memory chips they bought somewhere else, they did not particularly focus on making memory chips themselves. About 10 years after the introduction of the first CPUs, CPU designers introduced a type of static random access memory that could be built right into the CPU. They called it cache memory that was able to buffer a very small portion of the main memory.
