diff --git a/src/isolator/hei_isolation_node.cpp b/src/isolator/hei_isolation_node.cpp
new file mode 100644
index 0000000..a0bbf37
--- /dev/null
+++ b/src/isolator/hei_isolation_node.cpp
@@ -0,0 +1,126 @@
+#include <isolator/hei_isolation_node.hpp>
+
+namespace libhei
+{
+
+//------------------------------------------------------------------------------
+
+bool IsolationNode::analyze( const Chip & i_chip, AttentionType_t i_attnType,
+                             IsolationData & io_isoData ) const
+{
+    bool o_activeAttn = false; // Initially, assume no active attentions.
+
+    // Keep track of nodes that have been analyzed to avoid cyclic isolation.
+    pushIsolationStack();
+
+    // A rule for i_attnType must exist.
+    auto rule_itr = iv_rules.find( i_attnType );
+    HEI_ASSERT( iv_rules.end() != rule_itr );
+
+    // Get the returned BitString for this rule.
+    const BitString * bs = rule_itr->second->getBitString( i_chip );
+
+    // Ensure this BitString is not longer than the maximum bit field.
+    HEI_ASSERT( bs->getBitLen() <= sizeof(RegisterBit_t) * 8 );
+
+    // Find all active bits for this rule.
+    for ( RegisterBit_t bit = 0; bit < bs->getBitLen(); bit++ )
+    {
+        // Continue to the next bit if not active.
+        if ( !bs->isBitSet(bit) ) continue;
+
+        // At least one active bit was found.
+        o_activeAttn = true;
+
+        // Determine if this attention originated from another register or if it
+        // is a leaf in the isolation tree.
+        auto child_itr = iv_children.find( bit );
+        if ( iv_children.end() != child_itr )
+        {
+            // This bit was driven from an attention from another register.
+            // Continue down the isolation tree to look for more attentions.
+            bool attnFound = child_itr->second->analyze( i_chip, i_attnType,
+                                                         io_isoData );
+            if ( !attnFound )
+            {
+                // Something went wrong. There should have been an active
+                // attention. It's possible there is a bug in the Chip Data
+                // File. Or, it is also possible some other piece of code is
+                // clearing the attention before this code is able to analyze
+                // it. Another possibility is that the hardware it not behaving
+                // as expected. Since we really don't know what happened, we
+                // should not assert. Instead, add this bit's signature to
+                // io_isoData. If there are no other active attentions, the user
+                // application could use this signature to help determine, and
+                // circumvent, the isolation problem.
+                io_isoData.addSignature( Signature { i_chip, iv_hwReg.getId(),
+                                                     iv_hwReg.getInstance(),
+                                                     bit, i_attnType } );
+            }
+        }
+        else
+        {
+            // We have reached a leaf in the isolation tree. Add this bit's
+            // signature to io_isoData.
+            io_isoData.addSignature( Signature { i_chip, iv_hwReg.getId(),
+                                                 iv_hwReg.getInstance(),
+                                                 bit, i_attnType } );
+        }
+    }
+
+    // Analysis is complete on this node. So remove it from cv_isolationStack.
+    popIsolationStack();
+
+    return o_activeAttn;
+}
+
+//------------------------------------------------------------------------------
+
+void IsolationNode::addRule( AttentionType_t i_attnType,
+                             const Register * i_rule )
+{
+    // A rule for this attention type should not already exist.
+    HEI_ASSERT( iv_rules.end() == iv_rules.find(i_attnType) );
+
+    // The rule should not be null.
+    HEI_ASSERT( nullptr != i_rule );
+
+    // Add the new rule.
+    iv_rules[i_attnType] = i_rule;
+}
+
+//------------------------------------------------------------------------------
+
+void IsolationNode::addChild( uint8_t i_bit, const IsolationNode * i_child )
+{
+    // An entry for this bit should not already exist.
+    HEI_ASSERT( iv_children.end() == iv_children.find(i_bit) );
+
+    // The child register should not be null.
+    HEI_ASSERT( nullptr != i_child );
+
+    // Add the new rule.
+    iv_children[i_bit] = i_child;
+}
+
+//------------------------------------------------------------------------------
+
+std::vector<const IsolationNode *> IsolationNode::cv_isolationStack {};
+
+//------------------------------------------------------------------------------
+
+void IsolationNode::pushIsolationStack() const
+{
+    // Ensure this node does not already exist in cv_isolationStack.
+    auto itr = std::find( cv_isolationStack.begin(),
+                          cv_isolationStack.end(), this );
+    HEI_ASSERT( cv_isolationStack.end() == itr );
+
+    // Push to node to the stack.
+    cv_isolationStack.push_back( this );
+}
+
+//------------------------------------------------------------------------------
+
+} // end namespace libhei
+