Bus structure in Computer Organization

Bus structure in Computer Organization

A Bus is a collection of wires that connects several devices. 

Buses are used to send control signals and data between the processor and other components

This is to achieve a  reasonable speed of operation. 

In computer system all the peripherals are connected to microprocessor through Bus.

Types of Bus structure:

1. Address bus  
2. Data bus 
3. Control bus 
   

1. Address Bus:  

1. Address bus carry the memory address while reading from writing into memory.  
2. Address bus caary I/O post address or device address from I/O port.  
3. In uni-directional address bu only the CPU could  send address and other units could not address the microprocessor. 
4. Now a days computers are haing bi-directional address bus. 

2. Data Bus:

1. Data bus carry the data.
2. Data bus is a bidirectional bus.
3. Data bus fetch the instructions from memory.  
4. Data bus used to store the result of an instruction into memory. 
5. Data bus carry commands to an I/O device controller or port.  
6. Data bus carry data from a device controller or port.
7. Data bus issue data to a device controller or port.

3. Control Bus:

Different types of control signals are used in a bus:

1. Memory Read: This signal, is issued by the CPU or DMA controller when performing  a read operation with the memory. 
2. MemoryWrite: This signal isissued by the CPU or DMAcontroller when performing  a write operation with the memory. 
3. I/O Read: This signal isissued by the CPU when it is reading from an input port.
4. I/O Write: This signal is issued by the CPU when writing into an output port.
5. Ready: The ready is an input signal to the CPU generated in order to synchronize the  show memory or I/O ports with the fast CPU.

Eg. Address bus cable

A system bus is a single computer bus that connects the major components of a computer system, combining the functions of a data bus to carry information, an address bus to determine where it should be sent, and a control bus to determine its operation.

Q1. Is USB a bus?

Ans. A USB is a fast serial bus, which connect an electronic device to a computer. 

It is mostly used on personal computers. 

USB is used with mobile phones, video games, etc.

More topics from Computer Organization to read

Computer Organization and Architecture:

EasyExamNotes.com covered following topics in these notes.

1. Structure of desktop computers
2. Logic gates
3. Register organization
4. Bus structure
5. Addressing modes
6. Register transfer language
7. Direct mapping numericals
8. Register in Assembly Language Programming
9. Arrays in Assembly Language Programming

References:

1. William stalling ,“Computer Architecture and Organization” PHI
2. Morris Mano , “Computer System Organization ”PHI