Microcontroller Systems 2 ELEX 4325

SUBROUTINES

• Design subroutines in assembler.
• Design subroutines to modularize program structure.
• Test subroutines as individual entities.
• Use the monitor program CALL function to verify subroutine operation.
• Explain the correct methods of subroutine usage.
• Write subroutines to convert data among ASCII, HEX, and BCD.

INTERRUPTS AND INTERRUPT SERVICE ROUTINES

• Design interrupt service routines.
• Explain the concept of an interrupt.
• Enumerate the various kinds of possible interrupts.
• Explain the actions taken by the microcontroller when an interrupt occurs.
• Describe the HC12's vectored interrupt system.
• Describe the requirements of a routine to service an interrupt.
• Describe the concept of masking of interrupts.
• Draw a memory map to show the usage of the stack by the interrupt process and by the interrupt service routine.
• Explain the correct methods of interrupt usage.
• Describe the prioritization of multiple interrupts.
• Calculate the latency time for servicing an interrupt.

THE HC12's REAL-TIME INTERRUPT

• Apply the real-time interrupt to time events.
• Explain the flag setting and flag clearing processes.
• Explain the setting-up of the interrupt pseudovector.
• Identify the registers and bits that control the Real-Time interrupt.
• Design a program, including real-time interrupt to crudely keep track of and display the time of day.
• Observe the effect on program operation of various program parameters.
• Optimize the program operation.

THE HC12's SPI SYSTEM

• Interface the HC12 to SPI peripheral chips.
• Explain the concepts of synchronous serial data transfer.
• Identify the registers and bits that control the operation of the HC12's synchronous peripheral interface.
• Write and test subroutines to utilize the SPI to communicate with suitable peripheral chips.
• Select and use peripheral chips which can be used with the HC12's SPI interface such as a display controller and a time-keeping chip.
• Compare synchronous serial data transfer with asynchronous serial data transfer.

THE HC12's TIMER SYSTEM

• Apply the timer system to generate and measure waveforms.
• Explain the operation of the timer system.
• Identify the registers and bits that control the operation of the timer system.
• Describe the usage of timer functions by polling methods and by interrupt methods.
• Utilize the timer system to generate a delay time accurately.
• Generate an accurate square-wave using the timer system output compare feature.
• Generate a variable duty-cycle waveform.
• Generate a periodic very narrow pulse using two timer output compare channels.
• Generate multiple synchronized waveforms using timer channel 7.
• Measure the width of a pulse using the timer input capture capabilities.
• Measure the period of a waveform using timer input capture capabilities.
• Understand the limitations of the timer system.
• Measure long time periods with the timer overflow.
• Describe the use of the timer system to time and frequency measurements.
• Use the CFORC register to control critical timing of events.

THE HC12's SCI SYSTEM

• Use the SCI system to transfer information to and from a host computer.
• Describe the principles of asynchronous data communication.
• Identify the registers and bits that control the HC12's SCI system.
• Differentiate between the modes of asynchronous data transfer.
• Write a subroutine to send a character to the host.
• Write a subroutine to receive a character from the host.
• Write a subroutine to send a string to the host.
• Write a subroutine to receive a string from the host.
• Use the SCI receiver in interrupt mode.
• Use input from the host keyboard to control duty-cycle of a pulse-width modulated waveform for motor speed control.
• Describe the modes of operation of the SCI receiver wakeup function.

THE HC12's EEPROM

• Record programs and data in the HC12's EEPROM
• Identify the registers and bits that control the EEPROM functions
• Understand the limitations and advantages of the EEPROM memory compared to other forms of memory.
• Write a subroutine to erase portions of the HC12's EEPROM.
• Write a subroutine to write to EEPROM memory.
• Describe the block protection mechanisms for the EEPROM.

ARITHMETIC OPERATIONS

• Develop numerical algorithms in assembler language for data conversion and interpretation.
• Apply the multiply and divide instructions in number conversions and other applications.
• Evaluate alternate algorithms for number conversions and other applications.
• Understand and interpret binary-weighted fractions and fixed point numbers.
• Apply the DAA instruction correctly to the handling of BCD numbers.

HARDWARE INTERFACING

• Create an integrated system consisting of, for example, a keypad, a display device (e.g. LCD), and a motor.
• Write software to debounce a mechanical switch.
• Write subroutines to interpret the keypresses of a keyboard such as a HEX keypad.
• Write software to provide multiple synchronized waveforms to control the operation of a stepping motor.
• Write software to provide the pulse-width-modulated waveform to control the speed of a DC motor.
• Write software to handle the alarm interrupt from an external chip such as a clock chip.
• Write software to communicate data to display devices such as a liquid crystal display.
• Describe how to interface to external memory devices.

COMPUTER ARCHITECTURE

• Select appropriate applications for the HC12 microcontroller.
• Describe the features of Von Neumann and Harvard architectures.
• Describe the principle features of the bus structure.
• Describe methods of address decoding and external chip selection.
• Draw a memory map for the HC12.
• Describe remapping of the HC12's resources within the memory map.

INSTRUCTION EXECUTION

• Analyze the machine instructions of a microcontroller system.
• Describe the addressing modes for the HC12 instruction set.
• Describe the opcode structure for the HC12 instructions.
• Hand assemble and disassemble instructions, including indexed address mode instructions.
• Understand the process of instruction fetch and execution in the Motorola HC11 and HC12 microcontrollers.

Effective as of Fall 2003