Memory Addressing
The memory of a computer system consists of tiny electronic switches, with each switch in one of two states: open or closed. It is, however, more convenient to think of these states as 0 and 1, rather than open and closed. Thus, each switch can represent a bit. The memory unit consists of millions of such bits. In order to make memory more manageable, eight bits are grouped into a byte. Memory can then be viewed as consisting of an ordered sequence of bytes. Each byte in this memory is identified by its sequence number starting with 0, as shown in Figure 1. This is referred to as the memory address of the byte. Such memory is called byte addressable memory because each byte has a unique address.
Figure 1 Logical view of the system memory.
The Pentium can address up to 4 GB (232 bytes) of main memory (see Figure 1). This magic number comes from the fact that the address bus of the Pentium has 32 address lines. This number is referred to as the memory address space. The memory address space of a system is determined by the address bus width of the processor used in the system. The actual memory in a system, however, is always less than or equal to the memory address space. The amount of memory in a system is determined by how much of this memory address space is populated with memory chips.
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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