Add LATCH to target interface

ivl_target.h

@@ -336,7 +336,8 @@ typedef enum ivl_lpm_type_e {
       IVL_LPM_SUB    =  8,
       IVL_LPM_SUBSTITUTE=39,
       /* IVL_LPM_RAM =  9, / obsolete */
-      IVL_LPM_UFUNC  = 14
+      IVL_LPM_UFUNC  = 14,
+      IVL_LPM_LATCH  = 40
 } ivl_lpm_type_t;
 
 /* The path edge type is the edge type used to select a specific
@@ -1313,6 +1314,11 @@ extern unsigned    ivl_lpm_lineno(ivl_lpm_t net);
  * single ivl_lpm_data input are the same with, ivl_lpm_width. This
  * device carries a vector like other LPM devices.
  *
+ * - Latch (IVL_LPM_LATCH)
+ * This data is an asynchronous latch. The ivl_lpm_q output and
+ * single ivl_lpm_data input are the same with, ivl_lpm_width. This
+ * device carries a vector like other LPM devices.
+ *
  * - Memory port (IVL_LPM_RAM) (deprecated in favor of IVL_LPM_ARRAY)
  * These are structural ports into a memory device. They represent
  * address/data ports of a memory device that the context can hook to
@@ -1428,18 +1434,18 @@ extern unsigned    ivl_lpm_negedge(ivl_lpm_t net);
 extern ivl_nexus_t ivl_lpm_clk(ivl_lpm_t net);
   /* IVL_LPM_UFUNC */
 extern ivl_scope_t  ivl_lpm_define(ivl_lpm_t net);
-  /* IVL_LPM_FF */
+  /* IVL_LPM_FF IVL_LPM_LATCH*/
 extern ivl_nexus_t ivl_lpm_enable(ivl_lpm_t net);
   /* IVL_LPM_ADD IVL_LPM_CONCAT IVL_LPM_FF IVL_LPM_PART IVL_LPM_MULT
      IVL_LPM_MUX IVL_LPM_POW IVL_LPM_SHIFTL IVL_LPM_SHIFTR IVL_LPM_SUB
-     IVL_LPM_UFUNC IVL_LPM_SUBSTITUTE */
+     IVL_LPM_UFUNC IVL_LPM_SUBSTITUTE IVL_LPM_LATCH*/
 extern ivl_nexus_t ivl_lpm_data(ivl_lpm_t net, unsigned idx);
   /* IVL_LPM_ADD IVL_LPM_MULT IVL_LPM_POW IVL_LPM_SUB IVL_LPM_CMP_EQ
      IVL_LPM_CMP_EEQ IVL_LPM_CMP_EQX IVL_LPM_CMP_EQZ IVL_LPM_CMP_NEE */
 extern ivl_nexus_t ivl_lpm_datab(ivl_lpm_t net, unsigned idx);
   /* IVL_LPM_ADD IVL_LPM_FF IVL_LPM_MULT IVL_LPM_PART IVL_LPM_POW
      IVL_LPM_SUB IVL_LPM_UFUNC IVL_LPM_CMP_EEQ IVL_LPM_CMP_EQX
-     IVL_LPM_CMP_EQZ IVL_LPM_CMP_NEE IVL_LPM_SUBSTITUTE */
+     IVL_LPM_CMP_EQZ IVL_LPM_CMP_NEE IVL_LPM_SUBSTITUTE IVL_LPM_LATCH*/
 extern ivl_nexus_t ivl_lpm_q(ivl_lpm_t net);
 extern ivl_drive_t ivl_lpm_drive0(ivl_lpm_t net);
 extern ivl_drive_t ivl_lpm_drive1(ivl_lpm_t net);

t-dll-api.cc

@@ -1148,6 +1148,8 @@ extern "C" ivl_nexus_t ivl_lpm_enable(ivl_lpm_t net)
       switch (net->type) {
 	  case IVL_LPM_FF:
 	    return net->u_.ff.we;
+	  case IVL_LPM_LATCH:
+	    return net->u_.latch.we;
 	  default:
 	    assert(0);
 	    return 0;
@@ -1220,6 +1222,9 @@ extern "C" ivl_nexus_t ivl_lpm_data(ivl_lpm_t net, unsigned idx)
 	  case IVL_LPM_FF:
 	    assert(idx == 0);
 	    return net->u_.ff.d.pin;
+	  case IVL_LPM_LATCH:
+	    assert(idx == 0);
+	    return net->u_.latch.d.pin;
 
 	  case IVL_LPM_CONCAT:
 	  case IVL_LPM_CONCATZ:
@@ -1344,6 +1349,8 @@ extern "C" ivl_nexus_t ivl_lpm_q(ivl_lpm_t net)
 
 	  case IVL_LPM_FF:
 	    return net->u_.ff.q.pin;
+	  case IVL_LPM_LATCH:
+	    return net->u_.latch.q.pin;
 
 	  case IVL_LPM_MUX:
 	    return net->u_.mux.q;

t-dll.cc

@@ -2051,6 +2051,45 @@ void dll_target::lpm_ff(const NetFF*net)
       nexus_lpm_add(obj->u_.ff.d.pin, obj, 0, IVL_DR_HiZ, IVL_DR_HiZ);
 }
 
+void dll_target::lpm_latch(const NetLatch*net)
+{
+      ivl_lpm_t obj = new struct ivl_lpm_s;
+      obj->type  = IVL_LPM_LATCH;
+      obj->name  = net->name();
+      obj->scope = find_scope(des_, net->scope());
+      assert(obj->scope);
+      FILE_NAME(obj, net);
+
+      obj->width = net->width();
+
+      scope_add_lpm(obj->scope, obj);
+
+      const Nexus*nex;
+
+	/* If there is a clock enable, then connect it up to the FF
+	   device. */
+      if (net->pin_Enable().is_linked()) {
+	    nex = net->pin_Enable().nexus();
+	    assert(nex->t_cookie());
+	    obj->u_.latch.we = nex->t_cookie();
+	    assert(obj->u_.latch.we);
+	    nexus_lpm_add(obj->u_.latch.we, obj, 0, IVL_DR_HiZ, IVL_DR_HiZ);
+      } else {
+	    obj->u_.latch.we = 0;
+      }
+
+      nex = net->pin_Q().nexus();
+      assert(nex->t_cookie());
+      obj->u_.latch.q.pin = nex->t_cookie();
+      nexus_lpm_add(obj->u_.latch.q.pin, obj, 0,
+		    IVL_DR_STRONG, IVL_DR_STRONG);
+
+      nex = net->pin_Data().nexus();
+      assert(nex->t_cookie());
+      obj->u_.latch.d.pin = nex->t_cookie();
+      nexus_lpm_add(obj->u_.latch.d.pin, obj, 0, IVL_DR_HiZ, IVL_DR_HiZ);
+}
+
 /*
  * Make the NetMult object into an IVL_LPM_MULT node.
  */

t-dll.h

@@ -76,6 +76,7 @@ struct dll_target  : public target_t, public expr_scan_t {
       void lpm_compare(const NetCompare*);
       void lpm_divide(const NetDivide*);
       void lpm_ff(const NetFF*);
+      void lpm_latch(const NetLatch*);
       void lpm_modulo(const NetModulo*);
       void lpm_mult(const NetMult*);
       void lpm_mux(const NetMux*);
@@ -388,6 +389,18 @@ struct ivl_lpm_s {
 		  ivl_expr_t aset_value;
 		  ivl_expr_t sset_value;
 	    } ff;
+	    struct ivl_lpm_latch_s {
+		  unsigned negedge_flag :1;
+		  ivl_nexus_t we;
+		  union {
+			ivl_nexus_t*pins;
+			ivl_nexus_t pin;
+		  } q;
+		  union {
+			ivl_nexus_t*pins;
+			ivl_nexus_t pin;
+		  } d;
+	    } latch;
 
 	    struct ivl_lpm_mux_s {
 		  unsigned size;