The design process involves choosing an instruction set and a certain execution paradigm (e.g. VLIW or RISC) and results in a microarchitecture, which might be described in e.g. VHDL or Verilog.
For microprocessor design, this description is then manufactured employing some of the various semiconductor device fabrication processes, resulting in a die which is bonded onto a chip carrier.
Device types used to implement the logic include: A CPU design project generally has these major tasks: Re-designing a CPU core to a smaller die area helps to shrink everything (a "photomask shrink"), resulting in the same number of transistors on a smaller die.
Releasing a CPU on the same size die, but with a smaller CPU core, keeps the cost about the same but allows higher levels of integration within one very-large-scale integration chip (additional cache, multiple CPUs or other components), improving performance and reducing overall system cost.
The demands of being able to run a wide range of programs efficiently has made these CPU designs among the more advanced technically, along with some disadvantages of being relatively costly, and having high power consumption.
The main remaining area of active hardware design and research for scientific computing is for high-speed data transmission systems to connect mass market CPUs.
As measured by units shipped, most CPUs are embedded in other machinery, such as telephones, clocks, appliances, vehicles, and infrastructure.
[12] The 32-bit Parallax Propeller microcontroller architecture and the first chip were designed by two people in about 10 human years of work time.
For about a decade, every student taking the 6.004 class at MIT was part of a team—each team had one semester to design and build a simple 8 bit CPU out of 7400 series integrated circuits.
[16] Some undergraduate courses require a team of 2 to 5 students to design, implement, and test a simple CPU in a FPGA in a single 15-week semester.
[18] 24 people contributed to the 3.5 year MultiTitan research project, which included designing and building a prototype CPU.
[19] For embedded systems, the highest performance levels are often not needed or desired due to the power consumption requirements.