Data bus, Address bus, Control bus

Hard Disk Drives Data Bus

A collection of wires in which data is transmitted from one computer to another external drive. In personal computers, the data bus refers to internal bus. This is a bus that connects the internal computer components to the CPU and main memory. A bus is a common wire connecting various points in a circuit; examples are the ground bus and power bus. The data bus carries digital information.

A data bus is a group of wires connecting different parts of a circuit with wire carrying a different signal. The data bus is connected to the inputs of several gates and to the outputs of several gates. A data bus may be time multiplexed to serve different functions at different 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. For example, one line of the bus is used to indicate whether the CPU is currently reading from or writing to main memory. 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. For example, one line of the bus is used to indicate whether the CPU is currently reading from or writing to main memory. 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. For example, one line of the bus is used to indicate whether the CPU is currently reading from or writing to main memory.receive it. In general, information may flow on the bus wires in both directions. This type of bus is referred to as a bidirectional data bus.

There are two types of data bus; they are address bus and a data bus. The data bus transfers data and address bus transfers information about where the data should go. A bus which allows data to be transferred faster, which makes applications run faster. The local bus is of high-speed that connects directly to the processor. Many military systems are compatible with the 1553, but most new commercial systems are not. This system is used for command and telemetry transfer between military spacecraft components, subsystems and instruments, and within complex components themselves.

VME is a 32-bit architecture with a 40 Mb/s throughput. Peripheral Component Interconnect (PCI) Bus PCI is in widespread use in the computer industry. Although PCI was developed by Intel, it is not tied to any specific processor. It appears that PCI may eventually replace the older ISA bus and is competing with VME for industrial use. PCI can be 32 or 64-bits wide. It has peak transfer rates of 132 Mb/s, with a sustained transfer rates around 25 Mb/s. The PCI standard is maintained by the PCI Manufacturers although it is an open interface, only 3 or 4 manufacturers actually produce to it. The larger board size, requiring more volume than the other types of interfaces that have smaller form factors. The bus architecture which is developed by IBM for the PC/XT and PC/AT and adopted for industrial applications.

The main function of the data bus is to carry digital information. A data bus can be viewed as a group of wires connecting different parts of a circuit with wire carrying a different signal. The data bus is connected to the inputs of several gates and to the outputs of several gates. A data bus may be time multiplexed to serve different functions at different times. The ISA architecture which is also developed by IBM is used for defector standard, and is widely used for high performance. Thus, the main function of the data bus is to connect the system to the external devices. There are many types of data bus, which can connect the PC to the mobile and other external device in order to download software’s. Thus data bus is a media which is transfer the data from one place to another.

Address bus

is a computer bus, controlled by CPUs or DMA-capable peripherals for specifying the physical addresses of computer memory elements that the requesting unit wants to access (read or write).

The width of an address bus, along with the size of addressable memory elements, generally determines how much memory can be directly accessed. For example, a 16-bit wide address bus (commonly used in the 8-bit processors of the 1970s and early 1980s) reaches across 216 (65,536) memory locations , whereas a 32-bit address bus (common in PC processors as of 2004) can address 232 (4,294,967,296) locations. Some microprocessors, such as the Digital/Compaq Alpha 21264 and Alpha 21364 have an address bus that is narrower than the amount of memory they can address. The address bus is clocked faster than the system or memory bus, enabling it to transfer an address in the same amount of time as an address bus of the same width as the address.

In most microcomputers such addressable "locations" are 8-bit bytes, conceptually at least. In such case the above examples translate to 64 kilobytes (KB) and 4 gigabytes (GB) respectively. However, it should be noted that accessing an individual byte frequently requires reading or writing the full bus width (a word) at once. In these instances the least significant bits of the address bus may not even be implemented - it is instead the responsibility of the controlling device to isolate the individual byte required from the complete word transmitted. This is the case, for instance, with the VESA Local Bus which lacks the two least significant bits, limiting this bus to aligned 32 bit transfers.

Control bus

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. For example, one line of the bus is used to indicate whether the CPU is currently reading from or writing to main memory.