2 Replies Latest reply on Jul 8, 2017 12:45 PM by MiTu_2418356

    Opened input terminals in custom component design

      I am studying custom component creation using UDB.


      In usual, any input terminals added in symbol editor must be connected to something when using them in TopDesign.cysch, otherwise it results in an error such as:


      No input on Instance "MyComponent", terminal "Terminal_1".
      Terminal "Terminal_1" requires connection when it is visible.


      but I found that some cypress components can be compiled successfully without connections, e.g. 'en' and 'reset' terminals of the FreqDiv_v1_0 in CyComponentLibrary.


      Then I tried to copy 'en' and 'reset' terminals from the FreqDiv_v1_0 into my custom component by copy & paste, and found that the copied terminals worked without any connections!! Moreover, these copied 'en' and 'reset' terminals indicate '1' (high) and '0' (low) states respectively when there are no input connections. My example project is attached in this article.


      However, I cannot understand a reason why these terminals can be used without any input connections and they indicate '1' or '0' states deterministically. I want to know actual mechanisms about that. Does anyone have any ideas?