added license, moved cell libs into repo

added buffer (not tested),

test/unit_tests/helper.scm

@@ -0,0 +1,124 @@
+(define % (lambda (x y)  (- x (* y (truncate (/ x y))))))
+
+(define dualrail-bit
+  (lambda (x i)
+    (let ((tmp 
+	   (string-append x
+			  (string-append ".d["
+					 (string-append (number->string i)  "]")
+					 )
+			  )
+	   ))
+      (list (string-append tmp ".f") (string-append tmp ".t"))
+      )
+    )
+  )
+
+(define assert-var-bit
+  (lambda (x i v)
+    (let ((tmp (dualrail-bit x i)))
+      (begin
+	(assert (car tmp) (- 1 v))
+	(assert (cadr tmp) v)
+	)
+      )
+    )
+  )
+
+(define assert-var-int
+  (lambda (x width value)
+    (letrec ((assert-one-bit
+	      (lambda (v i)
+		(cond
+		 ((=? i width) #t)
+		 (#t (begin
+		       (assert-var-bit x i (% v 2))
+		       (assert-one-bit (truncate (/ v 2)) (+ i 1))
+		       )
+		     )
+		 )
+		)
+	      ))
+      (assert-one-bit value 0)
+      )
+    )
+  )
+	     
+(define assert-channel-valid
+  (lambda (ch width value)
+    (assert-var-int (string-append ch ".d") width value)
+    )
+  )
+
+(define assert-channel-neutral
+  (lambda (ch width)
+    (letrec ((helper
+	      (lambda (i)
+		(cond
+		 ((=? i width) #t)
+		 (#t (let ((tmp (dualrail-bit (string-append ch ".d") i)))
+			(begin
+			  (assert (car tmp) 0)
+			  (assert (cadr tmp) 0)
+			  (helper (+ 1 i))
+			  )
+			)
+		     )
+		 )
+		)
+	      )
+	     )
+      (helper 0)
+      )
+    )
+  )
+
+			
+(define set-channel-neutral
+  (lambda (ch width)
+    (letrec ((ch-name (string-append ch ".d"))
+	     (helper
+	      (lambda (i)
+		(cond
+		 ((=? i width) #t)
+		 (#t (let ((tmp (dualrail-bit ch-name i)))
+		       (begin
+			 (set (car tmp) 0)
+			 (set (cadr tmp) 0)
+			 (helper (+ 1 i))
+			 )
+		       )
+		     )
+		 )
+		)
+	      ))
+      (helper 0)
+      )
+    )
+  )
+
+(define set-channel-valid
+  (lambda (ch width val)
+    (letrec ((ch-name (string-append ch ".d"))
+	     (helper
+	      (lambda (i v)
+		(cond
+		 ((=? i width) #t)
+		 (#t (let ((tmp (dualrail-bit ch-name i)))
+		       (begin
+			 (set (car tmp) (- 1 (% v 2)))
+			 (set (cadr tmp) (% v 2))
+			 (helper (+ 1 i) (truncate (/ v 2)))
+			 )
+		       )
+		     )
+		 )
+		)
+	      ))
+      (helper 0 val)
+      )
+    )
+  )
+
+(define assert-var-bool  (lambda (x v) (assert-var-int x 1 v)))
+