title: Why do we need to Bit Extend the J type instruction to 2 bits only?
body: <p>Please have a look at this <code>Single Cycle Data Path</code> in <code>MIPS</code>. The <code>26 bits</code> of <code>J type instruction</code> are being Bit Extended to <code>28</code>. I don't get the point. Shouldn't it be extended to 31 so it makes <code>32</code> bits overall. Please help me out to clear the concept. 
  <img src="https://i.stack.imgur.com/tvHh2.png" alt="enter image description here">
  Thanks</p>