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Design
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* Start general
* Add more detail as you understand the problem
* Let it unfold


Design Objectives
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* Small clearly focused components
* Think of it as a bucket brigade
* Synchronize action with semphores
* Protect changes to data with semphores, mailboxes, queues
* Watch out for priority inversion. Use Mutexes where necessary.

Design Patterns
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* Worker tasks for interrupt handling

  * Do the interrupt handling work in a task not in the interrupt routine
  * Have a task waiting on a semphore
  * Have the interrupt routine signal the semphore


Top Down Diagram
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.. image:: Top_Down_Design_of_Music_Player.png
    :width: 650

Possible Design
===============

.. image:: Music_Player_Design.png
    :width: 600