CS255 Syllabus & Progress

• ASCII code: click here --- slides
• Unicode: click here --- slides

• Human <==> Computer communication (explains the need for conversion from ASCII to other representation and vice versa):
  • Introduction: keyboard input and terminal output devices click here --- slides

• Boolean input and output:
  • Pre-requisite: Java Strings click here --- slides
  • How to enter Boolean inputs - converting between ASCII String representation and Boolean representation: click here --- slides
  • How computers print out Boolean outputs - converting between Boolean representation to ASCII String representation: click here --- slides

• Numeric input/output - Converting between ASCII String representation and int 2's complement representation:
  • Introduction: click here --- slides

  • Java pre-requisites for String <==> Integer conversion:
    • The compiler translates every number in your program into a 2s complement binary representation: click here --- slides
    • Computing (calculations) with ASCII codes in Java: click here --- slides

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    • Java statements that manipulate characters and strings: click here --- slides

  • How to enter integer inputs - Conversion algorithm ASCII representation -> 2's complement representation:
    • Intro: what is the problem when you enter an integer number ? click here --- XXXXX slides
    • The trivial (but not-practical) solution: click here --- slides
    • Converting a string of 1 digit integer to 2's complement representation: click here --- slides
    • Converting a TWO DIGIT decimal integer string to 2's complement representation click here --- slides
    • Converting any decimal integer string to 2's complement representation click here --- slides
  • How computers print out integer values - Conversion algorithm 2's complement representation -> ASCII representation :
    • Intro: what is the problem when the program prints an integer number ? click here --- slides
    • The trivial (but not-practical) solution: click here --- slides
    • Converting a 1 digit decimal number to ASCII representation: click here --- slides
    • Converting a TWO-digits decimal number to ASCII representation: click here --- slides
    • Converting any decimal number to ASCII representation: click here --- slides

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    (My old notes on conversion algorithms: click here)

• Intro: what kinds of instructions can a computer execute ? click here --- slides
• Encoding computer instructions: click here --- slides
• Fixed length (RISC) vs. variable length (CISC) instruction formats: click here --- slides
• Sample instruction encodings:
  • M68000 Instruction encoding: click here -- no slides, read for your own interest
  • ARM Instruction encoding: click here -- no slides, read for your own interest

• Watch a YOUTUBE video on instruction set

• Introduction: click here --- slides

• The ARM processor's CPU architecture:
  • The ARM processor from the point of view of an assembler programmer: click here --- slides
  • EGTAPI's display of the registers: click here --- slides

• The "Hello World" program in assembler programming language: click here --- slides
• Program organization illustrated using the "Hello World" assembler program with the help of EGTAPI: click here --- slides

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• What does an assembler program contain ? (directives, instructions, comments and labels): click here --- slides

• The (program) text section/segment of an assembler program (and labels): click here --- slides
• The data section/segment of an assembler program (and labels): click here --- slides
  • Alignment requirements: click here --- slides

• Introduction: click here --- slides

• Moving an integer constant into a register
  • Moving a small integer value into a register: click here --- slides
    • Moving/copying an integer number from one register into another register: click here --- slides
  • Moving a large integer value into a register: click here --- slides
  • Moving an address into a register: click here --- slides

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• Reading (the value stored in) a simple memory variable: click here --- slides
• Writing/updating (the value stored in) a simple memory variable: click here --- slides
• Initializing and copying variables - simple high level programming statements in assembler: b = 4 and b = a click here --- slides

• Store-ordering in memory: big and little endian ordering click here --- slides

• What happens when you use an incorrect load/store instruction: click here --- slides

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  Project 4 re-enforces the use of move, load and store instructions: click here

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• Arithmetic operations (instructions): click here --- slides

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• Assignment statement involving (only) simple variables: the c = a + b statement in assembler click here --- slides

• Intro to data structures: --- slides

• How is an array data structure stored in computer memory: click here --- slides
• Defining an array in assembler: click here --- slides
• How to access an element in an array: click here --- slides
• Load and store assembler instruction formats used to access array data: click here --- slides

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• Assembler programming examples of accessing array: click here --- slides (1) --- slides (2) --- slides (3)

• How is an object stored in memory: click here --- slides
• How is a linked list stored in memory: click here --- slides      (I kept my old note here: old)

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• Defining the head reference variable to a link list in assembler: click here --- slides
• How to access a field in a (specific) list element: click here --- slides
• Assembler programming examples of accessing fields in a linked list: click here --- slides

• My summary notes on ARM assembler programming techniques used to prepare the CS255 material: click here
• A single sheet summary of ARM instruction nmenomic codes : click here
• Documentation - the complete ARM Instruction set and encoding (not part of syllabus material): click here

Now you know what the computer actually does when it executes an assignment statement: how it evaluates an expression and assigns the result to a variable in a high level programming language. We will discuss various program flow control structures next.

• Introduction: click here --- slides

• Branching - out of order program flow: click here --- slides
• How is the branch instruction implemented ? click here --- slides

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• The Compare (cmp) and Branch (beq, bne, blt, ble, bgt, bge, bal) assembler instructions of ARM: click here --- slides

• Coding Selection statements in assembler:
  • If-statement with a simple condition: click here --- slides
  • If-else-statement with a simple condition: click here --- slides
  • Compound condition using and: click here --- slides
  • Compound condition using or: click here --- slides

• While-statment: click here --- slides
• For-statment (sum an array): click here --- slides
• Traversing linked lists: click here --- slides
• Do-statment: click here. --- slides

The midterm test will cover the material upto this point and will be scheduled soon.

Now you know what the computer actually does when it runs a program. The only thing that you still do not know is what happens in a function call (there is still a lot to learn...).

• Introduction: click here --- slides

• Leaf subroutines and Non-Leaf subroutines: click here --- slides

• Leaf subroutines: subroutines (= functions) that do not call any function
  • Let's try to use what we have learned (branch) to implement subroutine call: click here --- slides
  • Calling a functions - ARM's bl (branch and link) instruction: click here --- slides
  • Returning from a leaf subroutine click here --- slides

• Non-leaf functions -- functions that calls another function....
  • What happens when a called function calls another function: click here --- slides
  • The program runtime stack of a running program: click here --- slides
  • The ARM assembler push and pop instructions: click here --- slides

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  • Implementing non-leaf methods/functions using the program stack: click here --- slides

• Using the non-leaf function technique to implement leaf functions: click here --- slides

• Introduction: click here --- slides

• Passing parameters to a function and passing return values using CPU registers:
  • Intro: using CPU registers to pass parameters and return values: click here --- slides
  • Sequencing of events in function call + return with parameters and return values: click here --- slides
  • sumSquares(a,b): using CPU registers to pass parameters and return values click here --- slides

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• sumRange(A, a, b): using registers as local variables: click here --- slides

• Caveat of using register to pass parameters and store local variables: click here --- slides
• A concrete example of the overwrite problem when using CPU registers: click here --- slides

• Passing parameters and allocating local variables using the program stack:
  • Intro: using the program stack to store parameters and local variables: click here --- slides 1 --- slides 2

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  • Why can the stack avoid the overwrite problem in registers: click here --- slides
  • How to code subroutine return in assembler --- tearing down a stack frame: click here --- slides

  • Summary and a "How to" guide: click here --- slides
  • A skeletal example: click here --- slides

  • A complete example of passing parameters and allocating local variables using the program stack: click here --- slides

• Another usage of the program stack - saving registers in an interrupted computation: click here --- slides

• Introduction: click here --- slides

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• First recursive method in assembler, the classic factorial function: click here --- slides

• Second recursive method in assembler: click here --- slides

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  Programming project pj8 re-enforces storing parameters and local variables on stack with a recursive function: click here

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  I inserted some material here to help you understand how to write program using the recursion technique --- these material are not part of CS255 curriculum:

  Recursion is a divide and conquer technique to solve problems: How to design recursive algorithms: click here --- slides Tower of Hanoi click here --- slides A Tower of Hanoi game page: click here A tougher example of divide and conquer using recursion: click here --- slides

  But I will discuss these webpages (quicker than usual) to help you understand the next topic: use recursion to manipulate linked lists

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• Tower of Hanoi in ARM assembler code: click here (skipped for brevity - read through it yourself)

• Introduction: click here --- slides

• Remember how linked lists are stored inside the computer: click here --- review slides

• Inserting a new element at the tail of the list using a recursive algorthm:
  • My CS170 page on designing a recursive "insert at tail of list" algorithm: click here --- slides
  • Implementing the recursive "insert at tail of list" algorithm in ARM assembler code: click here --- slides

• Introduction: click here --- slides
• Implementing Pass-by-value and Pass-by-reference mechanism in assembler: click here --- slides
• Important note: click here --- slides

If you understand everything so far, you now know exactly what is going on when a computer executes a program. You can apply what you learn and write assembler programs in any assembler language, e.g., Intel Pentium, IBM PowerChip, DEC Alpha, SunMicrosystem SPARC... To program with a new chip, all you need to learn are:

• its architecture (registers),
• the addressing modes
• the instruction mnemonic codes and what they do.

Abbreviated C teaching pages:

Introduction: How to learn a new programming language: slides Intro to C programming: slides Comparing C and Java: slides The "Hello World" program in C: slides main( ) arguments: slides Input/output operations in C: slides The C-compiler - 1-pass compilers and 2-pass compilers: slides Things in C that you must be aware as a Java programmer: C is not a OOP language: slides Automatic type conversions in C: slides Variable definition/declaration and variable usage in C: Local variables (scoping and life time): slides Global variables (scoping and life time): slides Special storage variables (static local and static global): slides Function definition/declaration and function usage in C: Defining functions, using/calling functions and parameter passing mechanism in C: slides Declaring functions: slides C programming practice: use header files to hold declarations (and type definitions): slides Structured variables: Arrays (one-dim and 2-dim): slides C struct and data type (like Java "objects"): slides The reference data type: Intro to the reference data type: slides The operations/operators on reference data types: slides Function with reference data types parameters - "DIY pass-by-reference": slides Pointer to user-defined (struct) typed variables: slides The (short-hand) pointer-member-access operator ->: slides Linked list in C: Intro to list programming in C: slides Allocating memory space for list elements (i.e., "creating list objects") in C: slides Inserting a new list element at the tail of a list: slides Deleting element at the start of a list: slides Pointer arithmetic and dynamic arrays: Intro to pinter arithmetic using dynamic arrays: slides Pointer arithmetic: slides The short-hand operator [ ]: slides *** The Final will cover all the material above this line *** Using the ++ operator to traverse an array: slides Debug C programs: slides

• Introduction to C programming: click here
• Things that are identical in Java and C (I have highlighted things that are different in blue): click here

• How a CS professional should learn a new programming language: click here

• Introduction to the C Pre-processor:
  • Intro: click here
  • Comments in C (/* ... */ or // ... ): click here
  • Macros (#define): click here
  • Including files (#include): click here
  • Conditional compilation: click here
  • A trick to prevent a file being included multiple times: click here

• C's data types: click here
• Defining variables in C: click here
• Defining and declaring variables: click here

• The const data type modifier: click here

• C's expressions: (minimal casting !!!)
  • Operations involving same and different data types: click here
  • Conversion rules in C: click here

• Printing values of the built-in data types: click here
• Reading in values of the built-in data types: click here

• Arithmetic Operators: click here ( +, -, *, / )

• Bit-wise-Operators: (used in CS350)
  • The bit-wise operators: ( &, |, ^, ~ ) click here
  • How to use the bit-wise operators: click here
  • Denoting bit patterns using values in base 2, 8 and 16: click here
  • Bit manipulation functions - clear a bit, set a bit, flip a bit and test a bit: click here

• Shift-Operators: (used in CS350) click here ( >>, << )
  • Intro: click here
  • Set bit at position n: click here
  • Clear bit at position n: click here
  • Flip bit at position n: click here
  • Test bit at position n: click here

• Assignment Operators: click here ( +=, -=, *=, /=, &=, |=, ~=, >>=, <<= )

• Increment/decrement Operators: click here ( ++, -- )

• Boolean data type and operations:
  • The Boolean data type and Boolean values in C: click here
  • Compare and Logic Operators: ( <, <=, >, >=, ==, !=, &&, ||, ! ) click here
  • Boolean variables in C: click here

• The conditional operator ?: click here
• The comma operator , click here
• The sizeof operator click here

• Priority and Associativity of the C operators click here

• Assignment Statement: click here
• Selection Statements (if, if-else, switch): click here
• Loop Statements (while, for, do-while): click here

• Defining and using one-dimensional array variables: click here
• Review: static and dynamic arrays: click here
• Array bound checks: click here

• Defining and using two-dimensional array variables: click here
• Declaring array variables: click here

• "Bit" arrays: click here

• Defining and calling a function in C: click here
• Array parameters click here

• No overloaded functions in C !!!! click here

• The Parameter passing mechanism of C: click here

• Automatic conversion of parameter types and return value types in function call:
  • Programming principles in a function call: click here
  • Automatic type conversion in function calls: click here

• Implicit function prototyping in C: click here
• Function declarations and their scope: click here

• Introduction to multiple file compilation: click here
• How to compile a multiple files C program: click here

• The importance of function declaration in multi-file C programs: click here
• Declaring function using header files: click here

• Specifying dependency between files --- makefiles: click here
• Structure of "make files": click here
• The make utility: click here
• Example of make file for a multi-file C program project: click here

• If time permits:
  • Inference rules used in makefiles: (if time permits) click here
  • Macros in makefiles: (if time permits) click here
  • Miscellaneous makefile stuff (line continuation, comment, ...): click here

• User-defined types: (i.e.: structures)
  • Defining and using struct type and variables: click here
  • typedef: giving a (shorter) name to struct click here
  • Always use header files to store the struct's and typedef's in your C program: click here

  • struct parameter variables are passed-by-value: click here

  • Size of a struct "object": click here

• Life time and scope of variables in C:
  • Review: Life time and Scope of the variables: click here

  • Kinds of variables in C: click here

  • Life time of variables in C (and when is a variable initialized ?): click here
  • Scope of variables in C:
    • Scoping rules for: (1) global, (2) static global and (3) static local variables: click here
    • Scoping rules for local and parameter variables in C: click here (pay attention !)

• Applying the scoping rules --- how to make sure variables in a C program are accessible in multi-files C programs
  • Intro: accessing variables in a multi-files C programs: click here
  • Making global variables accessible in multi-files C programs through declaration: click here

• Debugging a C program: (debugging will not be covered in the final)
  • Using the gdb debugger: click here
  • Debugging with printf: click here

• The reference data type and reference (pointer) variables (Java does NOT have this data type !!!)
  • Reference (pointer) data type and variables: click here
  • The reference (&) operator click here
  • Storing the result of reference (&) operator in reference data typed variables: click here
  • Using reference variables --- the dereference (*) operator: click here

  • First application of reference variables: pass parameters pass-by-reference: click here

• Pointer to user-defined type:
  • Pointer to user-defined (struct) variables: click here
  • The short-hand operator ->: click here

• Using pointers to create and maintain linked lists in C:
  • Introduction to linked lists in C: click here
  • Memory management - you must de-allocate list elements when you delete them !!! click here
  • Insert at head of list: click here
  • Delete at head of list: click here

• Pointer arithmetic and Arrays
  • Pointer arithmetic: click here
  • Accessing arrays with pointers : click here
  • The [ ] operator: click here
  • The equivalance of pointers and arrays in C: click here

  • Using the [ ] operator to implement Dynamic arrays: click here

  • The ++ and -- operators used in pointer arithmetic: click here

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• Take a look at precedence and associativity of the new C's operators that you have learned: click here

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• Strings in C --- arrays of char: click here
• Some Strings functions in C Standard library click here
• Array of Strings --- command line arguments: click here

• Special kinds of variables in C:
  • register variables: click here

• Function parameters:
  • Passing a function as a parameter to a function: click here

• The C99 standard: click here
• Obituary of Dennis Ritchie (co-inventory of C): click here

• A free Intel Macro Assembler (if you want to write assembler on your PC): RIGHT click here and SAVE AS
• An online documentation on Assembler programming with MASM: click here

• Intel Assembler Code Table: click here

• The Intel 80x86 CPU architecture: click here
• The Intel 80x86 directives: click here
• The Intel 80x86 Addressing modes: click here
• Arithmetic operations: click here
• Compare and Branch: click here
• Subroutine call and return: click here

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• The Art of Assembler Language Programming book: click here

  Check out chapter 6