Introduction to Assembly Language Programming

Overview

• 8 bit and 16 bit micro-controller architectures and instruction sets.
• Basic assembly programming techniques using variables, arrays and data structures
• The fundamental structured programming constructs of sequence, choice and iteration, and how they can be realised in assembly language code
• Structured programming techniques using flowcharts and pseudo-code and how to convert these into clear well documented assembler
• Techniques for programming of timers, peripherals and interrupt handling
• The hands on exercises also cover the use of simulation, debugging and in-circuit debugging techniques as well as techniques for in-system programming.

Course Benefits
Students successfully completing this course will have a sound understanding of the mechanisms by which micro-controllers function, structured assembly programming techniques, assembly code testing and debugging techniques, and programming of timers and peripherals using polling and interrupt driven approaches.

Course Contents
Microprocessor Architectures

• Microprocessors compared to micro-controllers
• Uses of small micro-controllers
• Harvard and Von-Neuman architectures compared
• Memory types found in micro-controllers
• Limitations of micro-controllers
• Overview of common small micro-processor architectures

Instruction Sets and Assembly Language Programming

• Anatomy of an instruction
• Types of instruction
• How an assembler converts assembly code into machine code (object code)
• Formats for saving object code in files
• Loading code into a micro-controller
• Features found in typical Integrated Development Environments (IDEs)
• How simulators and debuggers work
• In circuit debugging and in circuit emulation compared and contrasted

Registers and Peripherals

• Special Function Registers, Working Registers, General Purpose Registers
• Typical on chip peripherals - USARTS, A/D, Timers, I/O Ports
• Basic Input / Output ( I/O )

Basic Assembly Language Program Patterns and Templates

• Implementing if-then-else logic in assembler
• Implementing iteration loops in assembler
• Calling and returning from functions in assembler
• Understanding the concept of a stack
  • Hardware stacks and software stacks
  • Passing arguments to functions
  • Returning results from functions
  • Saving and restoring context when working with functions
• Dealing with segmented memory architectures

Interrupts and Interrupt Handling

• What is an interrupt
• Enabling and disabling interrupts
• Interrupt vectors
• Prioritising of interrupts
• Nesting of interrupts
• Masking of interrupts
• Saving and restoring context in interrupt handlers
• Polling vs. interrupt driven event handling

Basic Input Output Techniques

• Displaying patterns using LEDs
• Cycling through a sequence of patterns
  • Using software delays
  • Using polling for timer counter overflow to implement a delay
  • Using timer interrupts to implement a delay
• Using lookup tables to specify a sequence of patterns
• Driving 7/8 segment LED displays
• Buttons and keypads
  • Detecting button presses using polling / interrupt approaches
  • Interfacing to a 3 x 4 or 4 x 4 keypads

More Advanced Input Output Techniques

• Driving a simple two line LCD display controller
• Implementing RS232 communications using an on chip USART
• Implementing RS232 communications using "bit banging"

Tables, Arrays and Records

• Defining and implementing simple constant data lookup tables
• Defining and working with simple arrays
• Designing and implementing basic record oriented data structures

Maths

• Binary, octal, decimal and hexadecimal numbers
• Using 1's complement and 2's complement to represent negative numbers
• How maths libraries implement basic integer arithmetic functions
• Fixed point and floating point arithmetic
• Converting a binary number into a string of digit characters
• Implementing parity checking