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Difference Between Address Bus and Data Bus

Main Difference

The main difference between Address Bus and Data Bus is that the Address Bus is a bus that locates memory in the processor and identifies the physical address, whereas the Data Bus helps to transmit data from one device to another and transmits the data bidirectionally.

Address Bus vs. Data Bus

The address bus is an electronic pathway that transfers a physical address in the memory, whereas the data bus helps to transmit data from one device to another. The address bus carry address signals only, whereas the data bus is used to carry data signals only.

The address bus is a type of computer bus that helps to transfer a physical address in the memory, while the data bus helps to send and receive data among different computer components. The address bus identifies the physical address, whereas the data bus transmits the data bidirectionally. The address bus is a unidirectional (single or one way) bus; on the other hand, the data bus is bidirectional. The address bus is a type of computer bus that helps to transfer a physical address in the memory, whereas the data bus helps to send and receive data among different computer components.

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The address bus can send data only in one direction, whereas in the data bus, the data travel in both directions. The address bus transfers the I/O and memory addresses of the data, conversely data bus sends and receives data. In the address bus, the width indicates the amount of memory a system can address; on the other side, in the data bus width indicates the rate of transferring data. The address bus determines where the data should be stored in the memory location, whereas the data bus carries the data to be stored. The length of the 8085 address bus microprocessor is 16-bit, whereas the length of the data bus microprocessor is 8-bit.

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Comparison Chart

Address BusData Bus
It helps to transfer memory addresses.It sends and receives the data through circuit lines.
Nature
The address bus locates memory in the processor.It helps to transmit data from one device to another.
Used For
The address bus carries address signals only.The data bus is used to carry data signals only.
Length
The length of the 8085 address bus microprocessor is 16-bit.The length of the 8085 data bus microprocessor is 8-bit.
Direction
The address bus can send data only in one direction.The data travel in both directions like it can send and also receives the data.
Determines
It determines where the data should be stored.The data bus carries the data to be stored.
Purpose
It is a three-state bus to provide address information to the address bus.The three-state bus is the general-purpose data path.
Transfer Data
The address bus is a type of computer bus that helps to transfer a physical address in the memory.The data bus transfers data among different computer components.
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What is Adress Bus?

The address bus is a type of computer bus that helps to transfer a physical address in the memory. It is represented in binary form and also allows the data bus to access storage. It is unidirectional, and it can transfer data only in one direction. The CPU and DMA (direct memory access) use the address bus to locate physical addresses for communication, which help in reading/writing commands. The address bus is used by the computer processor to read and write from memory. It specifies the individual memory block of the physical address whenever the access is needed.

The CPU and DMA read/write all the address buses in the form of bits. Now modern computers have a different kind of address buses that are used to perform specific tasks. When a system wants to write data in the memory, it sends the write signal and places a write address on the address bus and then put specific data on the data bus. In the same way, when a system wants to read data from memory, it will send the read command/ signal on the address bus. When the memory receives the read signal, it will get that specific data from memory and place back the specific data on the data bus.

The address bus was developed to decrease the cost and to enhance the modular integration. A bus with a 32-bit width can address 232 memory blocks that are equivalent to 4GB memory space. Nowadays, new computers are using a 64-bit address bus, which can address 16 exbibytes of memory space with supporting OS, which is unlimited. It transmits the I/O of the data and memory addresses of the data.

What is Data Bus?

The data bus helps to transmit data from one device to another device. The data bus is bidirectional, and it helps to send and receive the data. It transmits the data in both directions. The data bus carries the data and then stored them in a specific location. It helps to send data among different computer components. In the data bus, the hardware component refers to wires and optical fiber. It consists of 83264 lines that indicate the data bus width. In data bus, width is the rate of transferring data. The width of the data bus also indicates the system performance, and the increment in the number of lines will be expensive.

The data bus is used to carry data signals only. A data bus is defined broadly in general. It carries the data; the internal buses carry or transfer information or data within the processor, whereas external buses transfer data among processor and memory. For the read and write operations, the same data bus is used. When a system called for the write command, the processor will put or place the written data on the data bus. Similarly, when a system calls for a read command, the memory controller will obtain the data from a certain memory block and then send it through the data bus.

The data bus speed also affects the overall processing performance of a computer system. 32-bit was the first standard of the data bus, but now new data buses can handle more amount of data. The term data bus is similar to the term electric busbar of electronics. It transfers data to and from the central processing unit and the memory. The data buses are the tools used to facilitate data transmission on demand. The three-state bus is the general-purpose data path.

Key Differences

  1. The address bus is a bus that locates memory in the processor, whereas the data bus helps to transmit data from one device to another device.
  2. The address bus is a unidirectional (single or one way) bus; on the other hand, the data bus is bidirectional.
  3. The address bus is a type of computer bus that helps to transfer a physical address in the memory, whereas the data bus helps to send and receive data among different computer components.
  4. The address bus can send data only in one direction, while in the data bus, the data travel in both directions like it can send and also receives the data.
  5. The address bus transfers the memory addresses of data, and I/O of the data; conversely, data bus sends and receives data.
  6. In address bus, the amount of memory a system can access indicates the width of the bus; on the other hand, the rate of transferring data indicates the width of the data bus.
  7. The address bus determines where the data should be stored in the memory location, whereas the data bus carries the data to be stored.
  8. The address bus identifies the physical address, while the data bus transmits the data bidirectionally.
  9. The address bus is used to carry address signals only; on the contrary, the data bus is used to carry data signals only.
  10. The address bus is a three-state bus to provide address information to the address bus, while the three-state data bus is the general-purpose data path.

Conclusion

A bus is a pathway that helps to connect two or more devices. The main difference in address bus and data bus is that the address bus helps to transfer a physical address in the memory, whereas the data bus helps to transmit data from one device to another while the control bus sends signals among different devices.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss