title: How to fix Xst:528 this signal is connected to multiple drivers
body: <p>I am receiving this error in my code,I think this error arises when we try to assign a variable different values in multiple always blocks,but in my case i am not doing so,but still receiving this error.</p>
  
  <p>ERRORS:</p>
  
  <pre><code> Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;0&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;1&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;2&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;3&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;6&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;1&gt;&lt;7&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;4&gt;&gt;; this signal is connected to multiple drivers.
  ERROR:Xst:528 - Multi-source in Unit &lt;Output_calc_debug&gt; on signal &lt;oc_out&lt;3&gt;&lt;5&gt;&gt;; this signal is connected to multiple drivers.
  </code></pre>
  
  <p>Module Code:</p>
  
  <pre><code>module Output_calc_debug(
   input clk,
  input wire signed [0:7]oc_in,
  input [0:2]pid,
  output reg signed[0:31]oc_out_1d);
  
  
  //Mapping 1D I/O list to 2d local vars
  reg signed[0:7]oc_out[0:3];
  
  
  always @(oc_out[0],oc_out[1],oc_out[2],oc_out[3])
  begin
  oc_out_1d[0:7]=oc_out[0];
  oc_out_1d[8:15]=oc_out[1];
  oc_out_1d[16:23]=oc_out[2];
  oc_out_1d[24:31]=oc_out[3];
  end
  
  /***code***/
  
  
  always @ (posedge clk)
  begin :OC_block
  
  
      if(oc_in[0:1]==2'd0)
      begin
  
          cr_x&lt;=oc_in[4:5]/2;
          cr_y&lt;=oc_in[4:5]%2;
          dr_x&lt;=oc_in[6:7]/2;
          dr_y&lt;=oc_in[6:7]%2;
  
          /***code***/
  
          if(cr_y&lt;dr_y) 
          begin
              cr_y&lt;=cr_y+2'b1; 
  oc_out[E]=oc_in;
  oc_out[E][4:5]=(cr_x * 2) + cr_y;
  path&lt;=E;    
          end
  
  
  /***code***/
  </code></pre>
  
  <blockquote>
    <p>Note: I am using oc_out variable as a 2d array for putting data into
    my 1d array oc_out_1d[as verilog doesn't support 2d arrays in i/o
    list] and updating my output variable in one always block and my 2d
    local array in another always block.</p>
  </blockquote>