At the time of the first exam, a student should be able to:

Number Systems

• Convert between binary, decimal, and hexadecimal numbers.
• Perform unsigned and signed (2's complement) binary arithmetic.

Microcontroller Components and ATmega32 Architecture

• Explain the purpose of the following components: clock circuit, control unit, memory, I/O.
• Describe the memory model used in the Harvard architecture.
• Describe and explain the purpose for the various memory types found on the ATmega32.
• Describe the memory model used on the ATmega32 including specific address ranges for registers, data memory and program memory.
• Describe the main assembly language tools and their position in the toolchain (assembler, simulator, downloader, debugger).
• Describe the role of AVR Studio and ATmon in the development process.
• Describe the ATmega32 register set:
  • Program Counter
  • Instruction Register
  • Stack Pointer
  • General Purpose Registers R0-R31 (and the differences between the first and last 16).
  • General Purpose Registers X, Y and Z (and the differences between these and R0-R25)
  • Status Register (and the H, S, V, N, Z and C flags)
• Explain the different addressing modes (direct, indirect).

ATmega32 Instruction Set

• Use the transfer, load/store, increment/decrement, branch, add and bit manipulation instructions to implement short programs.
• Analyze (determine memory and register (including status flags) contents) for short assembly language programs.
• Analyze the time required for a set of instructions to execute.

Assembly Programming

• Use assembler directives (.dseg, .cseg, .org, .byte, .db) and symbolic labels correctly within short assembly programs.
• Analyze a listing file to determine where instructions are stored in memory.
• Write delay loops that execute for a specified amount of time.
• Initialize the stack pointer.
• Use the stack for temporary storage.
• Call and return from subroutines correctly.
• Discuss the consequences of using the stack incorrectly.
• Configure ports as input and/or output ports.
• Write short assembly programs/subroutines that perform simple I/O.
• Explain the term masking and demonstrate its use.
• Copy data from program memory into data memory.

At the time of the second exam, a student should be able to:

LCD Display

• You will be given the following information:
  • E is hardwired to PORTC7.
  • RS is hardwired to PORTC6.
  • WR is hardwired to PORTD7 (active low).
  • RD is hardwired to PORTD7 (active low).
• Explain how the LCD controller knows the difference between commands and data sent to it via PORTA.
• Write a program that initializes the LCD using lcdInit.
• Write a subroutine that uses lcdDataWrite
to display characters from program memory on the LCD.
• Write a subroutine that uses lcdDataWrite
to display characters from data memory on the LCD.
• Explain why the LCD display did not work correctly during Lab 6 when the potentiometer was turned completely clockwise or counter-clockwise.

ADC Subsystem

• Describe the capabilities of the ATmega32's ADC subsystem.
• Calculate the resolution of a ADC given the min/max voltages and the number of bits used to represent the digital result.
• Write code to configure and use the ADC subsystem for single ended ADC on an arbitrary input channel using polling or interrupts.
• Explain how PORTA can be used for both digital and analog input.
• Describe the mapping between each bit in the digital result and the analog input voltage.

Interrupts

• Explain the difference between polled and interrupt-driven systems.
• Indicate where the interrupt vector table is located in memory.
• Describe the purpose of the interrupt vector table.
• Explain the purpose for having specific control registers associated with particular interrupts.
• Explain the purpose of the I bit in the SREG register.
• Differentiate the following two instructions: RETI and RET.
• Write a simple assembly interrupt service routine.
• Write a simple assembly program that initializes everything needed to enable a particular interrupt service routine.
• Given specific sample code, show how the stack is changed as a result of an interrupt.

Timer/Counter Subsystem

• Describe how the TCNT0 and OCR0 operate.
• Configure the Timer/Counter0 subsystem to tick at a specified clock rate.
• Write a function that uses the timer subsystem and polling to create a delay of arbitrary length (up to 5 seconds).
• Configure the Timer/Counter0 subsystem to cause an interrupt every X seconds (where X is a number between 1 and 32 ms).
• Write initialization code that configures all the necessary items so that an interrupt service routine is called correctly.

At the time of the final exam, a student should be able to:

Mixing C and Assembly

• Understand the GNU compiler's use of temporary and saved registers. In particular,
  • Explain the differences in how the GNU compiler handles temporary and saved registers.
  • Describe the steps that must be taken when using a temporary register in an assembly function that was called from C.
  • Describe the steps that must be taken when using a temporary register in assembly that calls a C function.
  • Describe the steps that must be taken when using a saved register in an assembly function that was called from C.
  • Describe the steps that must be taken when using a saved register in assembly that calls a C function.
• State which register GCC assumes contains zero at all times and describe how to accomodate this when writing assembly code that is mixed with C.
• Demonstrate proper use of the GCC syntax (be aware of the syntax differences between GCC and the AVR assembler).
• Describe how parameters are passed between C and assembly functions.
• Describe the purpose of an object file (.o).
• Explain the purpose of the linker used when compiling programs with GCC.
• Translate functions written in C into assembly functions.
• Translate functions written in assembly into C functions.
• Indicate when the extern and .global keywords are required and explain what they do.
• Interpret disassembled C code.
• Explain how local variables (inside C functions) are stored in memory.

Timer/Counter Subsystem

• Configure the Timer/Counter0 subsystem to operate in normal, CTC, PWM phase correct, and PWM fast modes
• Configure the Timer/Counter0 subsystem to tick at a specified clock rate.
• Configure the Timer/Counter0 subsystem to produce a waveform on OC0 with a specified frequence and duty cycle.
• Configure the Timer/Counter1 subsystem to produce a waveform on OC1 with a specified frequence and duty cycle.
• Configure the Timer/Counter1 subsystem to operate in input capture mode.
• Write a function that uses the timer subsystem to calculate the period a waveform connected to the ICP.
• Write initialization code that configures all the necessary items so that any of the Timer/Counter0 and Timer/Counter1 subsystem interrupt service routines are called correctly.
• Describe at least two examples of how the Timer/Counter subsystem's output pin action and input capture features can be used.
• Describe what causes the timer/counter subsystems to be activated (start counting).

© 2001-2007 Dr. Christopher C. Taylor

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Phone: 277-7339