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ATV INSTRUMENTATION DISPLAY

ATV INSTRUMENTATION DISPLAY . System Software Design Ed Raezer. General System Design. Motorola MC9S12C32 w/ 32k Bytes EEPROM, 2K Bytes RAM 16 MHz Bus Frequency Memory Requirements for Project 8K ROM, 1K RAM. Kernel Selection. Kernel Choice: MicroC/OS-II

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ATV INSTRUMENTATION DISPLAY

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  1. ATV INSTRUMENTATIONDISPLAY System Software Design Ed Raezer

  2. General System Design • Motorola MC9S12C32 w/ 32k Bytes EEPROM, 2K Bytes RAM • 16 MHz Bus Frequency • Memory Requirements for Project 8K ROM, 1K RAM

  3. Kernel Selection • Kernel Choice: MicroC/OS-II Real-time preemptive multitasking kernel with a 1 ms tick period • Configured for my program • Modify (os_cfg.h)

  4. Task Priority 4- Start Task 5- User Interface 6- RPM Task 7- Speed Task 8- Clock Task

  5. Start Task Description: -Initializations -Creates Tasks -Priority #4 -Period: once (at startup) -Execution time: 200 msec

  6. Clock Task Description: -Retrieves time from RTC -Updates time buffer -Period: 1 sec (Periodic) -Execution Time: 35 usec -L = .000035

  7. User Interface Task Description: -Monitors the buttons -Sets Clock -Activates LEDs -Changes Display Modes -Execution Time: 1 msec -Period: 10 ms -L = .1

  8. RPM Task Description: -Retrieves pulse count from pulse accumulator and converts to RPMs -Updates RPM buffer -Period: 500 msec -Execution Time: 20 usec -L = .00004

  9. Speed Task Description: -Monitors wheel sensor, counts pulses and converts to speed and distance -Updates odometer -Updates speed buffer -Execution time: 20 usec -Period: quick as 50msec (ISR driven) -L = .0004

  10. ISR • Creates a semaphore everytime a wheel sensor pulse is detected so Wheel Task can run • Period: up to 50 msec • Execution time: 300 nsec • L = .000006

  11. CPU Load L = .000035+.1+.00004+.0004+.000006= .100481 LMAX = 10.05%

  12. Modules and Functions

  13. Dataflow Diagram

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