The first chapter microcomputer principle and interface technology (knowledge summary)

Chapter One

1, computer system

Internal memory:

• Features: fast access speed, a relatively small capacity.
• Memory organized in units, each unit corresponds to a unique address.
• 1Byte each memory cell storing data.
• The number of memory called a memory unit.
• For term memory.
  • Storage Capacity: the amount of data stored. In bytes.
  • Operation to the memory:
    • Read: the contents of the memory cell taken CPU, does not change the original cell content.
    • Write: CPU information into the memory unit, the unit being covered with the original content.
• Classification (according to work):
  • A random access memory (RAM)
  • A read only memory (ROM)

Input / output interface:

• Interface is a bridge between the CPU and external devices.
• The main function:
  • Data buffer register;
  • Type or the signal level of conversion;
  • Achieve operational match between host and peripheral.

bus:

• Is a set of wires and associated control, a set of driving circuit.
• The transport address, data and control information channels between the various components of the computer system.
  • Address bus (AB)
  • A data bus (DB)
  • A control bus (CB)

Storage Capacity: the amount of data stored. In bytes.

The operations on the memory: Read (out), write (enter)

Divided according to work: a random access memory RAM, a read only memory ROM

Input / output interface:

• Interface is a bridge between the CPU and external devices

• The main function:
  • Data Storage buffer
  • Signal level or type of conversion
  • Achieve operational match between host and peripheral

2, the general work process microcomputer

2.1, the computer during execution of instructions

2.2, von Neumann computer

3, number conversion, encoding

Number conversion simple. !

1. Numerical Code:
   1. Binary code
   2. BCD code (BCD code, 8421BCD code)
2. Western character encoding:
   1. ASCII code