What is the purpose of the address bus?
The address bus carries the address of the piece of memory or I/O device to be read from or written to. It is a unidirectional bus, which is to say that data travels only one way; from the CPU to memory. The number of lines on the bus determines the number of addressable memory elements.
It is a group of wires or lines that are used to transfer the addresses of Memory or I/O devices. It us unidirectional. In Intel 8085 microprocessor, Address bus was of 16 bits. This means that Microprocessor 8085 can transfer maximum 16 bit address which means it can address 65,536 different memory locations.
- A control bus is a computer bus that is used by the CPU to communicate with devices that are contained within the computer. This occurs through physical connections such as cables or printed circuits.
- Intel 8086 is a 16 bit integer processor. It has 16-bit data bus and 20-bit address bus. The lower 16-bit address lines and 16-bit data lines are multiplexed (AD0-AD15). Since 20-bit address lines are available, 8086 can access up to 2 20 or 1 Giga byte of physical memory.
- The memory bus is a type of computer bus, usually in the form of a set of wires or conductors which connects electrical components and allow transfers of data and addresses from the main memory to the central processing unit (CPU) or a memory controller.
Address and data buses may have different widths, that is, they may carry different number of bits. Yes, memory bus usually means data bus (that carries the memory data). In isolation, the microprocessor, the memory and the input/output ports are interesting components, but they cannot do anything useful.
- The physical connections that carry control information between the CPU and other devices within the computer. Whereas the data bus carries actual data that is being processed, the control bus carries signals that report the status of various devices.
- control signal. A pulse or frequency of electricity or light that represents a control command as it travels over a network, a computer channel or wireless. In the data communications world, control signals typically travel the same path as the data either as separate packets or contained within the data packets.
- The word main is used to distinguish it from external mass storage devices such as disk drives. Other terms used to mean main memory include RAM and primary storage. The computer can manipulate only data that is in main memory. Now, most PCs come with a minimum of 32 megabytes of main memory.
For example, an 8-bit-byte-addressable machine with a 20-bit address bus (e.g. Intel 8086) can address 220 (1,048,576) memory locations, or one MiB of memory, while a 32-bit bus (e.g. Intel 80386) addresses 232 (4,294,967,296) locations, or a 4 GiB address space.
- In a computer, the Memory Address Register (MAR) is the CPU register that either stores the memory address from which data will be fetched from the CPU, or the address to which data will be sent and stored. In other words, MAR holds the memory location of data that needs to be accessed.
- An address bus is a computer bus architecture used to transfer data between devices that are identified by the hardware address of the physical memory (the physical address), which is stored in the form of binary numbers to enable the data bus to access memory storage.
- (1) A location of data, usually in main memory or on a disk. You can think of computer memory as an array of storage boxes, each of which is one byte in length. Each box has an address (a unique number) assigned to it. By specifying a memory address, programmers can access a particular byte of data.
Updated: 2nd October 2019