eliminate need for a register for the _f flag in the Fpga version

diff --git a/src/edu/berkeley/fleet/fpga/Fpga.java b/src/edu/berkeley/fleet/fpga/Fpga.java
index dc4e878..44e9f91 100644 (file)
--- a/src/edu/berkeley/fleet/fpga/Fpga.java
+++ b/src/edu/berkeley/fleet/fpga/Fpga.java
@@ -177,7 +177,8 @@ public class Fpga extends FleetTwoFleet {
                 pw.println("`define "+name+"_full    ("+name+"_r && !"+name+"_a)");
                 pw.println("`define "+name+"_empty  (!"+name+"_r && !"+name+"_a)");
                 if (dd.isInputDock()) {
-                    pw.println("`define drain_"+name+"  if ("+name+"_r && !"+name+"_a) "+name+"_a <= 1;");
+                    //pw.println("`define drain_"+name+"  if ("+name+"_r && !"+name+"_a) "+name+"_a <= 1;");
+                    pw.println("`define drain_"+name+"  "+name+"_a <= 1;");
                 } else {
                     pw.println("`define fill_"+name+"  "+name+"_r <= 1;");
                 }
@@ -186,49 +187,50 @@ public class Fpga extends FleetTwoFleet {
             pw.print("`define reset ");
             for(DockDescription bb : sd.ports()) {
                 String bb_name = bb.getName();
-                if (bb.isInputDock()) pw.print(bb_name+"_a <= 1; "+bb_name+"_f <= 0; ");
+                if (bb.isInputDock()) pw.print(bb_name+"_a <= 1; ");
                 else                  pw.print(bb_name+"_r <= 0; ");
             }
             pw.println();
 
             pw.print("`define cleanup ");
-            for(DockDescription bb : sd.ports()) {
-                String bb_name = bb.getName();
-                if (bb.isInputDock()) pw.print("if (!"+bb_name+"_r && "+bb_name+"_a) "+bb_name+"_a <= 0; ");
-                else                  pw.print("if ( "+bb_name+"_r && "+bb_name+"_a) "+bb_name+"_r <= 0; ");
-            }
+
+            // output docks
+            for(DockDescription dd : sd.ports())
+                if (!dd.isInputDock())
+                    pw.print("if ( "+dd.getName()+"_r && "+dd.getName()+"_a) "+dd.getName()+"_r <= 0; ");
+
+            // input docks: if all inputs are flushing, drain them all
+            pw.print("if (1");
             for(DockDescription bb : sd.ports())
                 if (bb.isInputDock())
-                    pw.print(" if (!"+bb.getName()+"_r_) "+bb.getName()+"_f <= 0; ");
-            pw.print("if (1");
+                    pw.print(" && "+bb.getName()+"_f");
+            pw.print(") begin ");
+            for(DockDescription bb : sd.ports())
+                if (bb.isInputDock())
+                    pw.print(bb.getName()+"_a <= 1; ");
+
+            // input docks: if no inputs are flushing, do normal stuff
+            pw.print("end else if (1");
             for(DockDescription bb : sd.ports())
                 if (bb.isInputDock())
-                    pw.print(" && "+bb.getName()+"_r_ && !"+bb.getName()+"_a");
+                    pw.print(" && !"+bb.getName()+"_f");
             pw.print(") begin ");
-            if (true) {
-                pw.print("if (1");
-                for(DockDescription bb : sd.ports())
-                    if (bb.isInputDock())
-                        pw.print(" && "+bb.getName()+"_d["+WIDTH_WORD+"] ");
-                pw.print(") begin ");
-                if (true) {
-                    for(DockDescription bb : sd.ports())
-                        if (bb.isInputDock())
-                            pw.print(bb.getName()+"_f <= 1; ");
-                }
-                pw.print(" end else if (0");
-                for(DockDescription bb : sd.ports())
-                    if (bb.isInputDock())
-                        pw.print(" || "+bb.getName()+"_d["+WIDTH_WORD+"] ");
-                pw.print(") begin ");
-                if (true) {
-                    for(DockDescription bb : sd.ports())
-                        if (bb.isInputDock())
-                            pw.print(" if (!"+bb.getName()+"_d["+WIDTH_WORD+"]) "+bb.getName()+"_f <= 1; ");
+
+            for(DockDescription bb : sd.ports())
+                if (bb.isInputDock())
+                    pw.print("if (!"+bb.getName()+"_r_ && "+bb.getName()+"_a) "+bb.getName()+"_a <= 0; ");
+
+            // input docks: if some-but-not-all inputs are flushing, drain all non-flushing docks
+            pw.print("end else begin ");
+
+            for(DockDescription bb : sd.ports())
+                if (bb.isInputDock()) {
+                    pw.print("if (!"+bb.getName()+"_r && "+bb.getName()+"_a) "+bb.getName()+"_a <= 0; ");
+                    pw.print("if ("+bb.getName()+"_r && !"+bb.getName()+"_a) "+bb.getName()+"_a <= 1; ");
                 }
-                pw.print(" end ");
-            }
-            pw.print(" end ");
+
+            pw.print(" end");
+
             pw.println();
             
             pw.println("module " + filename + "( clk, rst ");
@@ -279,9 +281,9 @@ public class Fpga extends FleetTwoFleet {
                     pw.println("        output  "+bb_name+"_a_;");
                     pw.println("        reg     "+bb_name+"_a;");
                     pw.println("        initial "+bb_name+"_a  = 0;");
-                    pw.println("        reg     "+bb_name+"_f;");
-                    pw.println("        initial "+bb_name+"_f  = 0;");
-                    pw.println("        assign  "+bb_name+"_a_ = "+bb_name+"_a || "+bb_name+"_f;");
+                    pw.println("        wire    "+bb_name+"_f;");
+                    pw.println("        assign  "+bb_name+"_f  = "+bb_name+"_r_ & "+bb_name+"_d["+width+"] && ~"+bb_name+"_a;");
+                    pw.println("        assign  "+bb_name+"_a_ = "+bb_name+"_a;");
                 } else {
                     pw.println("        output  ["+width+":0] "+bb_name+"_d_;");
                     pw.println("        input   "+bb_name+"_a;");
@@ -305,7 +307,7 @@ public class Fpga extends FleetTwoFleet {
                 pw.println("    end else begin");
                 pw.println("      `cleanup");
                 pw.println("      out_r <= out_r__;");
-                pw.println("      in_a  <= in_a__;");
+                pw.println("      if (in_a__) in_a  <= 1;");
                 pw.println("    end");
                 pw.println("  end");
             } else {