comp systems engineering
c 2004-2010 Steven S. Lumetta. All rights reserved.
1
ECE391: Computer Systems Engineering
Lecture Notes Set 0
Review Material
This set of notes reviews material that you have probably already seen in ECE190 or ECE290 (or CS225). If you took neither ECE190 nor CS225, some of it may be new to you; the TAs might also talk about some of this material in the first couple of discussion sections, and both MP1 and MP2 will require you to make use of it. Regardless of your previous experience, you may want to scan the list of terms at the end of these notes and review the definitions for any terms that seem unclear to you. In order to make the notes more useful as a reference, definitions are highlighted with boldface, and italicization emphasizes pitfalls.
The notes begin with a review of how information is represented in modern digital computers, highlighting the use of memory addresses as pointers to simplify the representation of complex information types. The next topic is the systematic decomposition of tasks into subtasks that can be executed by a computer, and an example based on a pointer-based data structure. Moving on to high-level languages, and particularly the C language, the notes continue with a review of type and variable declarations in C as well as the use of structures, arrays, and new types. The next topic is C operators, with some discussion of the more subtle points involved in their use. After revisiting the decomposition example as written in C, the notes discuss implicit and explicit conversions between types. Finally, the notes conclude with a review of C’s preprocessor. We deliberately omit the basics of C syntax as well as descriptions of C conditional (if/else and switch) and iteration (while, do, and for loops) statements.
Representation as Bits
Modern digital computers represent all information as sets of binary digits, i.e., 0s and 1s, or bits. Whether you are representing something as simple as an integer or as
1
ECE391: Computer Systems Engineering
Lecture Notes Set 0
Review Material
This set of notes reviews material that you have probably already seen in ECE190 or ECE290 (or CS225). If you took neither ECE190 nor CS225, some of it may be new to you; the TAs might also talk about some of this material in the first couple of discussion sections, and both MP1 and MP2 will require you to make use of it. Regardless of your previous experience, you may want to scan the list of terms at the end of these notes and review the definitions for any terms that seem unclear to you. In order to make the notes more useful as a reference, definitions are highlighted with boldface, and italicization emphasizes pitfalls.
The notes begin with a review of how information is represented in modern digital computers, highlighting the use of memory addresses as pointers to simplify the representation of complex information types. The next topic is the systematic decomposition of tasks into subtasks that can be executed by a computer, and an example based on a pointer-based data structure. Moving on to high-level languages, and particularly the C language, the notes continue with a review of type and variable declarations in C as well as the use of structures, arrays, and new types. The next topic is C operators, with some discussion of the more subtle points involved in their use. After revisiting the decomposition example as written in C, the notes discuss implicit and explicit conversions between types. Finally, the notes conclude with a review of C’s preprocessor. We deliberately omit the basics of C syntax as well as descriptions of C conditional (if/else and switch) and iteration (while, do, and for loops) statements.
Representation as Bits
Modern digital computers represent all information as sets of binary digits, i.e., 0s and 1s, or bits. Whether you are representing something as simple as an integer or as