CMPSCI 503 - Embedded Systems

Widget Interface Specification (WIS)

  • Widget Interface Standard (WIS) (Prelimary Draft) - (Updated 12-03-03) (HTML 12-03-03) (Draft Standard 11/20/03)
  • Original analyis to see how much we can push the network. (Updated 11-20-03) (HTML 11-15-03)
  • An updated, more complete and detailed analysis. (Updated 12-03-03) (HTML 12-03-03)
  • A photo of some hubs. (Updated 12-19-03)

    A problem was reported with the network when someone tries to add or reconnect a widget onto the network. My guess is that some devices pull the bus low prior to complete initialization. As a result, a "glitch" is sent on the network. For such problematic devices, I recommend placing a tri-state buffer before the WIS connector on the widget and enabling the buffer after the device has initialized. This should eliminate the problem. A hub-based alternative solution has not been proposed, but I feel this tri-state buffer recommendation is a solid solution.


  • Image of the Digital Clock widget that I constructed. - (Updated 12-19-03)
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    Contact - wacko at emulationzone d0t org
    Last updated: 01-11-04
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