1. System Software Design Dane Kim May 4 th, 2009 EET 475, WWU

2. General System Design  MCU: Cypress PSoC CY8C29446  8-bit  Bus Frequency: 24 MHz  Memory Requirements:  5K ROM  <1K RAM  Kernel: Timeslice

3. Tasks, ISRs and CPU Load Task/ISRPurposePeriod (ms) Execution Time ( s) TimeSlice TaskMaintain slice period5010 Instrumentation TaskCalculate Speed and RPM Collect A/D samples for temp Calculate odometer value Poll for blinkers, other indicators 50150 LCD TaskUpdate instrumentation info on LCD50 Manage user interface Button TaskScans and debounces button presses10 Speed Timer ISRStarts/stops timer for speedometer34 (min)8.3 Tachometer Timer ISRStarts/stops timer for tachometer10 (min)8.3 Button Press ISRIndicates button press (debounced in LCD task)30.1 Shutdown ISRSenses low voltage and stores odometer dataNA Lmax = (10  s) + (150  s) + (50  s) + (10  s) + (8.3  s) + (8.3  s) + (.1  s) = 12.4% (10ms) (50ms) (50ms) (10ms) (30ms) (10ms) (30ms) Lave = 9.07%

4. Module/Library Description Module NameTasksPublic FunctionsPublic Data Main.cTimeSlice Instrumentation LCD Button LCD.cDisplay() Instrumentation.cSpeedCalc() TachCalc() TempSense() OdoCalc() IndiSense() LCD.asm (Cypress API) Delsig8.asm (Cypress API) TachTimer.asm (Cypress API) SpeedTimer.asm (Cypress API) Dac8.asm (Cypress API)

5. Data Flow Diagram – Speed/RPM Speedometer Timer Input Speed/Tach Timer ISR Instrumentation.c Instrumentation Task DataReady Timer Data DataRead

6. Data Flow Diagram - Temp A-to-D I/O DelSig A/D Instrumentation.c TempRead() DelSig_Result Start Read

7. Data Flow Diagram – Button LCD Task Button Task Button Pressed 1. Button Press

8. Data Flow Diagram - LCD LCD I/O LCD.c Struct InstrData Application LCD Task

9. Data Flow Diagram – Indicator Lights Turn Signal/ Neutral Gear/ High Beam I/O Instrumentation.c Indicator Data Instrumentation Task Main.c