From 6446add9cd3fdc2fa03cc72456a10a5a89781ed9 Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Sun, 23 Apr 2000 21:15:07 +0000
Subject: [PATCH]  Emit code for the bufif devices.

---
 netlist.h        |  8 ++++++--
 t-xnf.cc         | 44 ++++++++++++++++++++++++++++++++++++--------
 vvm/vvm_gates.cc | 43 ++++++++++++++++++++++++++++++++++++++++---
 vvm/vvm_gates.h  | 19 ++++++++++++++++++-
 4 files changed, 100 insertions(+), 14 deletions(-)

diff --git a/netlist.h b/netlist.h
index 7bc8255e4..82db0b469 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.128 2000/04/23 03:45:24 steve Exp $"
+#ident "$Id: netlist.h,v 1.129 2000/04/23 21:15:07 steve Exp $"
 #endif
 
 /*
@@ -823,7 +823,8 @@ class NetConst  : public NetNode {
 
 /*
  * This class represents all manner of logic gates. Pin 0 is OUTPUT and
- * all the remaining pins are INPUT
+ * all the remaining pins are INPUT. The BUFIF[01] gates have the
+ * additional restriction that pin 1 is the enable.
  */
 class NetLogic  : public NetNode {
 
@@ -2440,6 +2441,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.129  2000/04/23 21:15:07  steve
+ *  Emit code for the bufif devices.
+ *
  * Revision 1.128  2000/04/23 03:45:24  steve
  *  Add support for the procedural release statement.
  *
diff --git a/t-xnf.cc b/t-xnf.cc
index 17d72d68d..c4272ec22 100644
--- a/t-xnf.cc
+++ b/t-xnf.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-xnf.cc,v 1.24 2000/04/20 02:34:47 steve Exp $"
+#ident "$Id: t-xnf.cc,v 1.25 2000/04/23 21:15:07 steve Exp $"
 #endif
 
 /* XNF BACKEND
@@ -773,21 +773,46 @@ void target_xnf::logic(ostream&os, const NetLogic*net)
 	  case NetLogic::XOR:
 	    os << "XOR";
 	    break;
+	  case NetLogic::BUFIF0:
+	  case NetLogic::BUFIF1:
+	    os << "TBUF";
+	    break;
 	  default:
-	    cerr << "XNF: Unhandled logic type." << endl;
+	    cerr << "internal error: XNF: Unhandled logic type." << endl;
 	    break;
       }
       os << ", LIBVER=2.0.0" << endl;
 
+	/* All of these kinds of devices have an output on pin 0. */
       draw_pin(os, "O", net->pin(0));
 
-      if (net->pin_count() == 2) {
+	/* Most devices have inputs called I<N> for all the remaining
+	   pins. The TBUF devices are slightly different, but
+	   essentially the same structure. */
+      switch (net->type()) {
+
+	  case NetLogic::BUFIF0:
+	    assert(net->pin_count() == 3);
+	    draw_pin(os,  "I", net->pin(1));
+	    draw_pin(os, "~T", net->pin(2));
+	    break;
+
+	  case NetLogic::BUFIF1:
+	    assert(net->pin_count() == 3);
 	    draw_pin(os, "I", net->pin(1));
-      } else for (unsigned idx = 1 ;  idx < net->pin_count() ;  idx += 1) {
-	    string name = "I";
-	    assert(net->pin_count() <= 11);
-	    name += (char)('0'+idx-1);
-	    draw_pin(os, name, net->pin(idx));
+	    draw_pin(os, "T", net->pin(2));
+	    break;
+
+	  default:
+	    if (net->pin_count() == 2) {
+		  draw_pin(os, "I", net->pin(1));
+	    } else for (unsigned idx = 1; idx < net->pin_count(); idx += 1) {
+		  string name = "I";
+		  assert(net->pin_count() <= 11);
+		  name += (char)('0'+idx-1);
+		  draw_pin(os, name, net->pin(idx));
+	    }
+	    break;
       }
 
       os << "END" << endl;
@@ -828,6 +853,9 @@ extern const struct target tgt_xnf = { "xnf", &target_xnf_obj };
 
 /*
  * $Log: t-xnf.cc,v $
+ * Revision 1.25  2000/04/23 21:15:07  steve
+ *  Emit code for the bufif devices.
+ *
  * Revision 1.24  2000/04/20 02:34:47  steve
  *  Generate code for identity compare. Use gates.
  *
diff --git a/vvm/vvm_gates.cc b/vvm/vvm_gates.cc
index 0b389ffc6..e0a97823f 100644
--- a/vvm/vvm_gates.cc
+++ b/vvm/vvm_gates.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vvm_gates.cc,v 1.12 2000/03/22 04:26:41 steve Exp $"
+#ident "$Id: vvm_gates.cc,v 1.13 2000/04/23 21:15:07 steve Exp $"
 #endif
 
 # include  "vvm_gates.h"
@@ -149,6 +149,38 @@ void vvm_buf::take_value(unsigned, vpip_bit_t val)
       output(outval);
 }
 
+vvm_bufif0::vvm_bufif0(unsigned long d)
+: vvm_1bit_out(d)
+{
+      input_[0] = StX;
+      input_[1] = StX;
+}
+
+vvm_bufif0::~vvm_bufif0()
+{
+}
+
+void vvm_bufif0::init_I(unsigned key, vpip_bit_t val)
+{
+      assert(key < 2);
+      input_[key] = val;
+}
+
+void vvm_bufif0::take_value(unsigned key, vpip_bit_t val)
+{
+      if (input_[key] == val) return;
+      input_[key] = val;
+
+      if (! B_IS0(input_[1]))
+	    output(HiZ);
+      else if (B_ISXZ(input_[0]))
+	    output(StX);
+      else if (B_IS1(input_[0]))
+	    output(St1);
+      else
+	    output(St0);
+}
+
 vvm_bufif1::vvm_bufif1(unsigned long d)
 : vvm_1bit_out(d)
 {
@@ -160,8 +192,10 @@ vvm_bufif1::~vvm_bufif1()
 {
 }
 
-void vvm_bufif1::init_I(unsigned, vpip_bit_t)
+void vvm_bufif1::init_I(unsigned key, vpip_bit_t val)
 {
+      assert(key < 2);
+      input_[key] = val;
 }
 
 void vvm_bufif1::take_value(unsigned key, vpip_bit_t val)
@@ -173,7 +207,7 @@ void vvm_bufif1::take_value(unsigned key, vpip_bit_t val)
 	    output(HiZ);
       else if (B_ISXZ(input_[0]))
 	    output(StX);
-      else if (B_IS1(val))
+      else if (B_IS1(input_[0]))
 	    output(St1);
       else
 	    output(St0);
@@ -285,6 +319,9 @@ void vvm_not::take_value(unsigned, vpip_bit_t val)
 
 /*
  * $Log: vvm_gates.cc,v $
+ * Revision 1.13  2000/04/23 21:15:07  steve
+ *  Emit code for the bufif devices.
+ *
  * Revision 1.12  2000/03/22 04:26:41  steve
  *  Replace the vpip_bit_t with a typedef and
  *  define values for all the different bit
diff --git a/vvm/vvm_gates.h b/vvm/vvm_gates.h
index 47a87b377..e307a2df2 100644
--- a/vvm/vvm_gates.h
+++ b/vvm/vvm_gates.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vvm_gates.h,v 1.59 2000/04/23 03:45:25 steve Exp $"
+#ident "$Id: vvm_gates.h,v 1.60 2000/04/23 21:15:07 steve Exp $"
 #endif
 
 # include  "vvm.h"
@@ -567,6 +567,20 @@ class vvm_buf  : public vvm_1bit_out, public vvm_nexus::recvr_t {
       void take_value(unsigned, vpip_bit_t val);
 };
 
+class vvm_bufif0  : public vvm_1bit_out, public vvm_nexus::recvr_t {
+
+    public:
+      explicit vvm_bufif0(unsigned long d);
+      ~vvm_bufif0();
+
+      void init_I(unsigned, vpip_bit_t);
+      void start() { }
+
+    private:
+      vpip_bit_t input_[2];
+      void take_value(unsigned key, vpip_bit_t val);
+};
+
 class vvm_bufif1  : public vvm_1bit_out, public vvm_nexus::recvr_t {
 
     public:
@@ -916,6 +930,9 @@ class vvm_posedge  : public vvm_nexus::recvr_t {
 
 /*
  * $Log: vvm_gates.h,v $
+ * Revision 1.60  2000/04/23 21:15:07  steve
+ *  Emit code for the bufif devices.
+ *
  * Revision 1.59  2000/04/23 03:45:25  steve
  *  Add support for the procedural release statement.
  *