diff --git a/cpu/samd21/include/samd21.h b/cpu/samd21/include/samd21.h
index 5e25deddcb..d7bc359131 100644
--- a/cpu/samd21/include/samd21.h
+++ b/cpu/samd21/include/samd21.h
@@ -1,4 +1,4 @@
-/**
+/*
  * \file
  *
  * \brief Header file for SAMR21G18A
diff --git a/doc/doxygen/riot.doxyfile b/doc/doxygen/riot.doxyfile
index 91d917e8bf..7215647390 100644
--- a/doc/doxygen/riot.doxyfile
+++ b/doc/doxygen/riot.doxyfile
@@ -813,6 +813,8 @@ EXCLUDE_SYMLINKS       = NO
 EXCLUDE_PATTERNS       = */board/*/tools/* \
                          */cpu/*/include/component/* \
                          */cpu/*/include/instance/* \
+                         */cpu/*/include/pio/* \
+                         */cpu/lpc*/include/core_cm*.h \
                          */cpu/cortex-*_common/include/core_cm*.h \
                          */cpu/cortex-*_common/include/core_cmInstr.h \
                          */cpu/cortex-*_common/include/core_cmFunc.h \