data path

control unit (CU)

stored-program computer

memory hierarchy

cache memory

virtual memory

I/O devices

system-on-chip (SoC)

operands

program counter (PC) (aka instruction pointer (IP) in x86)

instruction register (IR)

pipelining

physical address space

address space

memory-mapped I/O (MMIO)

port-mapped I/O (PMIO)

bus

• address bus
• data bus
• control bus

arithmetic logic unit (ALU)

general-purpose register (GPR)

instruction set architecture (ISA) (or architecture) is an abstract interface between the hardware and the lowest-level software that encompasses all the information necessary to write a machine language program that will run correctly, including instructions, registers, memory access, I/O, and so on

• RISC (reduced instruction set computer)
  • RISC-V is an open-source ISA based on established RISC principles
  • Examples: MIPS, ARM
• CISC (complex instruction set computer)
  • Examples: x86, PowerPC

word

• word size (or word length) is the number of bits in a word
• word size may be used for:
  • registers: the number of bits in a general-purpose register
  • memory addresses: the number of bits in a memory address
  • instructions
  • data types (e.g., integer, floating-point, character)
  • address bus
  • data bus
• e.g., 32 bits in MIPS, 64 bits in x86-64, or 16 bits in the 8086

register is a small, fast storage location within the CPU used to store data temporarily

• register file
• The process of putting less commonly used variables (or those needed later) into memory is called spilling registers