add dff to techlib

.gitignore

@@ -1,12 +1,14 @@
-__pycache__
+__pycache__/
 .ipynb_checkpoints
 .pytest_cache
 .DS_Store
-*.pyc
-docs/_build
-build
-dist
 .idea
 .vscode
-src/kyupy.egg-info
+.venv
+*.py[oc]
+docs/_build
+build/
+dist/
+wheels/
+*.egg-info
 *nogit*

src/kyupy/sim.py

@@ -272,10 +272,10 @@ class SimOps:
 
         # allocate and keep memory for PI/PPI, keep memory for PO/PPO (allocated later)
         for i, n in enumerate(circuit.s_nodes):
-            if len(n.outs) > 0:
+            if 'dff' in n.kind.lower() or len(n.ins) == 0:  # PPI or PI
                 self.c_locs[self.ppi_offset + i], self.c_caps[self.ppi_offset + i] = h.alloc(c_caps_min), c_caps_min
                 ref_count[self.ppi_offset + i] += 1
-            if len(n.ins) > 0:
+            if len(n.ins) > 0:  # PO
                 i0_idx = stems[n.ins[0]] if stems[n.ins[0]] >= 0 else n.ins[0]
                 ref_count[i0_idx] += 1
 

src/kyupy/techlib.py

@@ -98,6 +98,7 @@ OA211   input(i0,i1,i2,i3) output(o) o=OA211(i0,i1,i2,i3)  ;
 AOI211  input(i0,i1,i2,i3) output(o) o=AOI211(i0,i1,i2,i3) ;
 OAI211  input(i0,i1,i2,i3) output(o) o=OAI211(i0,i1,i2,i3) ;
 MUX21   input(i0,i1,i2)    output(o) o=MUX21(i0,i1,i2)     ;
+DFF     input(D,CLK)       output(Q) Q=DFF(D,CLK)        ;
 """)
 """A synthetic library of all KyuPy simulation primitives.
 """