from PART I - PRELIMINARIES
Published online by Cambridge University Press: 05 November 2012
A long-standing source of confusion is the order of bits in binary strings. This issue is very important when strings of bits are serially communicated or stored in memories. Consider the following two scenarios.
In the first setting, Alice wishes to send to Bob a binary string a[n − 1 : 0]. The channel that Alice and Bob use for communication is a serial channel. This means that Alice can only send one bit at a time. Now Alice has two natural choices:
She can send a[n − 1] first and a[0] last; namely, she can send the bits in descending index order. This order is often referred to as most significant bit first or just MSB first.
She can send a[0] first and a[n − 1] last; namely, she can send the bits in ascending index order. This order is often referred to as least significant bit first or just LSB first.
In the second setting, computer words are stored in memory. A memory is a vector of storage places. We denote this vector by M[0], M[1],. … Suppose that each storage place is capable of storing a byte (i.e., 8 bits). The typical word size in modern computers is 32 bits (and even 64 bits). This means that a word is stored in four memory slots. The question is, how do we store a word a[31 :0]in four memory slots?
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.