diff --git a/portable/ThirdParty/xClang/XCOREAI/portasm.S b/portable/ThirdParty/xClang/XCOREAI/portasm.S
index 019f2b875..64b7b9d9a 100644
--- a/portable/ThirdParty/xClang/XCOREAI/portasm.S
+++ b/portable/ThirdParty/xClang/XCOREAI/portasm.S
@@ -14,7 +14,8 @@ rest of the ISR callback functions. */
 .issue_mode dual
 .cc_top kexcept.function, kexcept
 kexcept:
-  bu _DoException
+  bu _DoException       /* This symbol is generated by the toolchain and */
+                        /* provides graceful exception handling */
 
 _yield:
  {set    sp,     r4                  /* Restore the task's SP to save the rest of its context. */