diff --git a/core/lib/assert.c b/core/lib/assert.c
index fcbed9743e..e8b27723d8 100644
--- a/core/lib/assert.c
+++ b/core/lib/assert.c
@@ -18,6 +18,7 @@
 #include "assert.h"
 #include "architecture.h"
 #include "cpu.h"
+#include "debug.h"
 #include "panic.h"
 #if IS_USED(MODULE_BACKTRACE)
 #include "backtrace.h"
@@ -30,6 +31,7 @@ __NORETURN void _assert_failure(const char *file, unsigned line)
     printf("failed assertion. Backtrace:\n");
     backtrace_print();
 #endif
+    DEBUG_BREAKPOINT(1);
     core_panic(PANIC_ASSERT_FAIL, "FAILED ASSERTION.");
 }
 
@@ -39,6 +41,7 @@ __NORETURN void _assert_panic(void)
 #if IS_USED(MODULE_BACKTRACE)
     backtrace_print();
 #endif
+    DEBUG_BREAKPOINT(1);
     core_panic(PANIC_ASSERT_FAIL, "FAILED ASSERTION.");
 }
 
diff --git a/core/lib/include/debug.h b/core/lib/include/debug.h
index 4d93e3eee6..7c67b26155 100644
--- a/core/lib/include/debug.h
+++ b/core/lib/include/debug.h
@@ -59,6 +59,27 @@ extern "C" {
 #define DEBUG_PRINT(...) printf(__VA_ARGS__)
 #endif
 
+/**
+ * @def DEBUG_BREAKPOINT
+ *
+ * @brief Set a debug breakpoint
+ *
+ * When `DEVELHELP` is enabled, this traps the CPU and allows to debug the
+ * program with e.g. `gdb`.
+ * Without `DEVELHELP` this turns into a no-op.
+ *
+ * @warning     If no Debugger is attached, the CPU might get stuck here
+ *              and consume a lot of power until reset.
+ *
+ * @param val   Breakpoint context for debugger, usually ignored.
+ */
+#ifdef DEVELHELP
+#include "architecture.h"
+#define DEBUG_BREAKPOINT(val)   ARCHITECTURE_BREAKPOINT(val)
+#else
+#define DEBUG_BREAKPOINT(val)   (void)0
+#endif
+
 /**
  * @name Debugging defines
  * @{
diff --git a/cpu/cortexm_common/include/architecture_arch.h b/cpu/cortexm_common/include/architecture_arch.h
index a393f6db6b..8bb8897691 100644
--- a/cpu/cortexm_common/include/architecture_arch.h
+++ b/cpu/cortexm_common/include/architecture_arch.h
@@ -26,7 +26,8 @@ extern "C" {
 
 /* Doc is provided centrally in architecture.h, hide this from Doxygen */
 #ifndef DOXYGEN
-#define ARCHITECTURE_WORD_BITS      (32U)
+#define ARCHITECTURE_WORD_BITS          (32U)
+#define ARCHITECTURE_BREAKPOINT(value)  __BKPT(value)
 #endif /* DOXYGEN */
 
 #ifdef __cplusplus
diff --git a/cpu/native/include/architecture_arch.h b/cpu/native/include/architecture_arch.h
index ef3ebf2fa5..1a9f7ae06d 100644
--- a/cpu/native/include/architecture_arch.h
+++ b/cpu/native/include/architecture_arch.h
@@ -24,9 +24,17 @@
 extern "C" {
 #endif
 
+/**
+ * @brief raise SIGTRAP
+ *
+ *        We must not include signal.h directly into RIOT application namespace.
+ */
+void native_breakpoint(void);
+
 /* Doc is provided centrally in architecture.h, hide this from Doxygen */
 #ifndef DOXYGEN
 #define ARCHITECTURE_WORD_BITS      (32U)
+#define ARCHITECTURE_BREAKPOINT(v)  native_breakpoint()
 #endif /* DOXYGEN */
 
 #ifdef __cplusplus
diff --git a/cpu/native/native_cpu.c b/cpu/native/native_cpu.c
index 7e0cf5aaa5..5e9e96875a 100644
--- a/cpu/native/native_cpu.c
+++ b/cpu/native/native_cpu.c
@@ -99,6 +99,11 @@ int thread_isr_stack_usage(void)
     return -1;
 }
 
+void native_breakpoint(void)
+{
+    raise(SIGTRAP);
+}
+
 static inline void *align_stack(uintptr_t start, int *stacksize)
 {
     const size_t alignment = sizeof(uintptr_t);
diff --git a/cpu/stm32/periph/dac.c b/cpu/stm32/periph/dac.c
index 468bfa6c4a..c043269711 100644
--- a/cpu/stm32/periph/dac.c
+++ b/cpu/stm32/periph/dac.c
@@ -73,18 +73,15 @@ void dac_set(dac_t line, uint16_t value)
 {
     assert(line < DAC_NUMOF);
 
-    /* scale set value to 12-bit */
-    value = (value >> 4);
-
-#ifdef DAC_DHR12R2_DACC2DHR
+#ifdef DAC_DHR12L2_DACC2DHR
     if (dac_config[line].chan & 0x01) {
-        dev(line)->DHR12R2 = value;
+        dev(line)->DHR12L2 = value;
     }
     else {
-        dev(line)->DHR12R1 = value;
+        dev(line)->DHR12L1 = value;
     }
 #else
-    dev(line)->DHR12R1 = value;
+    dev(line)->DHR12L1 = value;
 #endif
 }
 
diff --git a/sys/include/architecture.h b/sys/include/architecture.h
index ebd7ce1c31..90f9febd6d 100644
--- a/sys/include/architecture.h
+++ b/sys/include/architecture.h
@@ -33,6 +33,19 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Set a breakpoint
+ * @warning         If no Debugger is attached, the CPU might get stuck here
+ *                  and consume a lot of power until reset.
+ * @param[in] value Context value for debugger, usually ignored.
+ */
+#ifndef ARCHITECTURE_BREAKPOINT
+/* If no breakpoint instruction is defined, busy wait for debugger
+ * to attach and break to ease backtrace
+ */
+#define ARCHITECTURE_BREAKPOINT(value)  do {} while (1)
+#endif
+
 /* Provide doxygen doc centrally, instead of in every architecture_arch.h */
 #ifdef DOXYGEN
 /**
diff --git a/tests/unittests/Makefile b/tests/unittests/Makefile
index ea1caca504..2d3fb7472f 100644
--- a/tests/unittests/Makefile
+++ b/tests/unittests/Makefile
@@ -3,12 +3,14 @@ include ../Makefile.tests_common
 
 USEMODULE += embunit
 
-ifeq (, $(filter tests-%, $(MAKECMDGOALS)))
-  # the $(dir) Makefile function leaves a trailing slash after the directory
-  # name, therefore we use patsubst instead.
-  UNIT_TESTS := $(patsubst %/Makefile,%,$(wildcard tests-*/Makefile))
-else
-  UNIT_TESTS := $(filter tests-%, $(MAKECMDGOALS))
+ifeq (, $(UNIT_TESTS))
+  ifeq (, $(filter tests-%, $(MAKECMDGOALS)))
+    # the $(dir) Makefile function leaves a trailing slash after the directory
+    # name, therefore we use patsubst instead.
+    UNIT_TESTS := $(patsubst %/Makefile,%,$(wildcard tests-*/Makefile))
+  else
+    UNIT_TESTS := $(filter tests-%, $(MAKECMDGOALS))
+  endif
 endif
 
 DISABLE_MODULE += auto_init auto_init_%