Editing Spec.isa (section)

=== Example 1 - Overture ===
The Overture specification provides a good starting example:
<pre>
register
r0 000
r1 001
r2 010
r3 011
r4 100
r5 101
in 110
out 110
</pre>
Here we can see a couple of features:
* Names are arbitrary.  <code>r0</code> through <code>r5</code> are considered registers only by convention, while <code>in</code> and <code>out</code> follow an entirely different naming scheme within the same <code>register</code> field.
* Value repetition is allowed.  <code>in</code> and <code>out</code> both have the same value of <code>110</code>.
* Completion is not required.  <code>111</code> is not assigned to any label.