tailieunhanh - Understanding Automotive Electronics 5 Part 5

Tham khảo tài liệu 'understanding automotive electronics 5 part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | MICROCOMPUTER INSTRUMENTATION AND CONTROL 4 Microprocessor Architecture Understanding how the microprocessor operates is aided by Figure which is a block diagram of a typical commercial microprocessor. This block diagram is divided into two main portions a register section and a control section. The actual operations performed by the microprocessor are Figure Typical Microprocessor Internal Architecture Irtr ftnoi UNDERSTANDING AUTOMOTIVE ELECTRONICS 109 4 MICROCOMPUTER INSTRUMENTATION AND CONTROL The first step in starting up a computer is initialization. accomplished in the register section. The specific operations performed during the execution of a given step in the program are controlled by electrical signals from the instruction decoder. During each program step an instruction in the form of an 8-bit or possibly 16-bit number is transferred from memory to the instruction register. This instruction is decoded using logic circuits similar to those presented in Chapter 3. The result of this decoding process is a set of electrical control signals that are sent to the specific components of the register section that are involved in the instruction being executed. The data upon which the operation is performed is similarly transferred from memory to the data bus buffer. From this buffer the data is then transferred to the desired component in the register section for execution of the operation. Note that an arithmetic and logic unit ALU is included in the register section of the typical microprocessor is shown in Figure . This device is a complex circuit capable of performing the arithmetic and logical operations as explained in Chapter 3. Also included in the register section is the accumulator which is the register used most frequently to receive the results of arithmetic or logical operation. In addition the example microprocessor register section has an index register stack pointer register and program counter register. The program counter register .