table of Contents
2.1 A brief history of computers
2.3.1 Clock speed and number of instructions per second
2.1 A brief history of computers
1. "Five Generations": Electronic Tube Computer Era --> Transistor Computer Era --> Integrated Circuit Computer Era --> Large Scale Integrated Circuit Computer Era --> Very Large Scale Integrated Circuit Computer Era.
2. The basic feature of the working mode of von Neumann machines is to access and execute instructions sequentially.
3. Part of the register
① Memory buffer register (MBR): Contains a word that will be written to the memory or sent to the I/O unit or received from the memory or I/O unit.
② Memory address register (MAR): Specify the address of the memory word unit that will be written from the MBR into the memory or read from the memory into the MBR.
③ Instruction register (IR): contains the 8-bit opcode instruction being executed.
④ Instruction buffer register (IBR): used to temporarily store the right instruction of a word from the memory.
⑤ Program counter (PC): Store the address of the next pair of instructions to be fetched from the memory.
⑥ Accumulator (AC) and multiplier register (MQ): used to temporarily store the operands and results of ALU operations.
4. Moore's Law: Moore observes that the number of transistors that can be contained on a single chip doubles every year, and correctly asserts that this trend will continue in the near future.
2.2 Embedded system and ARM
2.2.1 Embedded System
It is a combination of computer hardware, software, and possibly additional machinery or other parts, used to perform specific functions. In many cases, embedded systems are part of large-scale products and systems
Generally, an embedded system is closely related to its environment.
2.2.2 ARM
ARM chips are high-speed processors and are most widely used in embedded systems.
2.3 Performance evaluation
2.3.1 Clock speed and number of instructions per second
1. System clock: The pulse rate is defined as the clock frequency, or clock speed. Each additional pulse or clock is called a clock cycle, or clock tick.
2. Command execution speed
① The average number of cycles per instruction (CPI)
② Millions of instructions per second (MIPS)
2.3.2 Amdahl's Law
Using a parallel system with N processors, the acceleration of the entire parallel part is as follows:
