diff --git a/test/unit_tests/helper.scm b/test/unit_tests/helper.scm
index 5acebcd..8a0879e 100644
--- a/test/unit_tests/helper.scm
+++ b/test/unit_tests/helper.scm
@@ -145,3 +145,94 @@
     )
   )
 )
+
+(define assert-data-bit
+  (lambda (x i v)
+    (let ((tmp (string-append x (string-append ".d[" (string-append (number->string i)  "]")))))
+        (assert tmp v)
+      )
+    )
+  )
+
+(define assert-data-int
+  (lambda (x width value)
+    (letrec ((assert-one-data-bit
+          (lambda (v i)
+        (cond
+         ((=? i width) #t)
+         (#t (begin
+               (assert-data-bit x i (% v 2))
+               (assert-one-data-bit (truncate (/ v 2)) (+ i 1))
+              )
+         )
+        )
+        )
+      ))
+      (assert-one-data-bit value 0)
+    )
+  )
+)
+
+(define assert-bd-channel-valid
+  (lambda (ch width value)
+    (begin
+      (assert-data-int ch width value)
+      (assert (string-append ch ".r") 1)
+    )
+  )
+)
+
+(define assert-bd-channel-neutral
+  (lambda (ch width)
+    (assert (string-append ch ".r") 0)
+    )
+  )
+
+  (define set-bd-channel-neutral
+  (lambda (ch width)
+    (letrec ((ch-name (string-append ch ".d"))
+         (helper
+          (lambda (i)
+            (cond
+              ((=? i width) #t)
+              (#t (let ((tmp (string-append ch (string-append ".d[" (string-append (number->string i) "]" )))))
+                    (begin
+                      (set tmp 0)
+                      (helper (+ 1 i))
+                    )
+                  )
+              )
+            )
+          )
+        ))
+        (begin 
+          (helper 0)
+          (set (string-append ch ".r") 0)
+        )
+    )
+  )
+)
+
+(define set-bd-channel-valid
+  (lambda (ch width val)
+    (letrec ((ch-name (string-append ch ".d"))
+         (helper
+          (lambda (i v)
+            (cond
+              ((=? i width) #t)
+              (#t (let ((tmp (string-append ch (string-append ".d[" (string-append (number->string i)  "]")))))
+                (begin
+                  (set tmp (% v 2))
+                  (helper (+ 1 i) (truncate (/ v 2)))
+                )
+              ))
+            )
+         )
+        ))
+      (begin
+        (helper 0 val)
+        (set (string-append ch ".r") 1)
+      )
+    )
+  )
+)
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