A computer system consists of three major components: a processor, a memory unit, and an input/output (I/O) subsystem. Interconnection network facilitates communication among these three components, as shown in Figure 21. The interconnection network is called the system bus.
The term “bus” is used to represent a group of electrical signals or the wires that carry these signals. As shown in Figure 1.5, the system bus consists of three major components: an address bus, a data bus, and a control bus.
The address bus width determines the amount of physical memory addressable by the processor. The data bus width indicates the size of the data transferred between the processor and memory or an I/O device. For example, the Pentium processor has 32 address lines and 64 data lines. Thus, the Pentium can address up to 232, or 4 GB of memory. Furthermore, each data transfer can move 64 bits of data.
The control bus consists of a set of control signals. Typical control signals include memory read, memory write, I/O read, I/O write, interrupt, interrupt acknowledge, bus request, and bus grant. These control signals indicate the type of action taking place on the system bus. For example, when the processor is writing data into the memory, the memory write signal is generated. Similarly, when the processor is reading from an I/O device, it generates the I/O read signal.
A bus connects various components in a computer system. Thus buses can be categorize into:
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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