move resolving cells to circuit, more doc

src/kyupy/circuit.py

@@ -314,6 +314,16 @@ class Circuit:
     def get_or_add_fork(self, name):
         return self.forks[name] if name in self.forks else Node(self, name)
 
+    def remove_dangling_nodes(self, root_node:Node):
+        if len([l for l in root_node.outs if l is not None]) > 0: return
+        lines = [l for l in root_node.ins if l is not None]
+        drivers = [l.driver for l in lines]
+        root_node.remove()
+        for l in lines:
+            l.remove()
+        for d in drivers:
+            self.remove_dangling_nodes(d)
+
     def eliminate_1to1_forks(self):
         """Removes all forks that drive only one node.
 
@@ -356,8 +366,6 @@ class Circuit:
         node_out_lines = list(node.outs) + [None] * (len(impl_out_lines)-len(node.outs))
         assert len(node_in_lines) == len(impl_in_lines)
         assert len(node_out_lines) == len(impl_out_lines)
-        in_lines_map = dict(zip(impl_in_lines, node_in_lines))
-        out_lines_map = dict(zip(impl_out_lines, node_out_lines))
         node.remove()
         node_map = dict()
         ios = set(impl.io_nodes)
@@ -370,13 +378,16 @@ class Circuit:
         for l in impl.lines:  # add all internal lines to main circuit
             if l.reader in node_map and l.driver in node_map:
                 Line(self, (node_map[l.driver], l.driver_pin), (node_map[l.reader], l.reader_pin))
-        for l, ll in in_lines_map.items():  # connect inputs
+        for l, ll in zip(impl_in_lines, node_in_lines):  # connect inputs
             if ll is None: continue
             ll.reader = node_map[l.reader]
             ll.reader_pin = l.reader_pin
             ll.reader.ins[ll.reader_pin] = ll
-        for l, ll in out_lines_map.items():  # connect outputs
-            if ll is None: continue
+        for l, ll in zip(impl_out_lines, node_out_lines):  # connect outputs
+            if ll is None:
+                if l.driver in node_map:
+                    self.remove_dangling_nodes(node_map[l.driver])
+                continue
             if len(l.reader.outs) > 0:  # output is also read by impl. circuit, connect to fork.
                 ll.driver = node_map[l.reader]
                 ll.driver_pin = len(l.reader.outs)
@@ -385,6 +396,13 @@ class Circuit:
                 ll.driver_pin = l.driver_pin
             ll.driver.outs[ll.driver_pin] = ll
 
+    def resolve_tlib_cells(self, tlib):
+        """Substitute all technology library cells with kyupy native simulation primitives.
+        """
+        for n in list(self.nodes):
+            if n.kind in tlib.cells:# and 'DFF' not in n.kind and 'LATCH' not in n.kind:
+                self.substitute(n, tlib.cells[n.kind][0])
+
     def copy(self):
         """Returns a deep copy of the circuit.
         """

src/kyupy/sdf.py

@@ -40,8 +40,11 @@ class DelayFile:
 
         All IOPATH delays for a node ``n`` are annotated to the line connected to the input pin specified in the IOPATH.
 
-        Only supports two delvals per delval_list. First delval is rising/posedge, second delval is falling/negedge
+        Limited support of SDF spec:
+        * ABSOLUTE delay values only
+        * two delvals per delval_list. First is rising/posedge, second is falling/negedge
           transition at the output of the IOPATH (SDF spec, pp. 3-17).
+        * PATHPULSE declarations are ignored.
 
         * Axis 0: dataset (usually 3 datasets per SDF-file)
         * Axis 1: line index (e.g. ``n.ins[0]``, ``n.ins[1]``)

src/kyupy/techlib.py

@@ -128,11 +128,6 @@ class TechLibNew:
     def pin_is_output(self, kind, pin):
         return self.cells[kind][1][pin][1]
 
-    def resolve(self, circuit):
-        for n in list(circuit.nodes):
-            if n.kind in self.cells:
-                circuit.substitute(n, self.cells[n.kind][0])
-
 
 NANGATE = TechLibNew(r"""
 FILLCELL_X{1,2,4,8,16,32} ;