Document.

4 files changed, 7 insertions, 10 deletions

diff --git a/cpu/alu.ml b/cpu/alu.ml
index e0c1ef9..f437bd3 100644
--- a/cpu/alu.ml
+++ b/cpu/alu.ml
@@ -51,7 +51,7 @@ let rec nadder_with_carry n a b c_in =
 
 let nadder n a b =
     let a, b = nadder_with_carry n a b (const "0") in
-    ignore b a
+    b ^. a
 
 let rec nsubber n a b =
     zeroes n (* TODO *)
diff --git a/cpu/cpu.ml b/cpu/cpu.ml
index 541e364..94cc47c 100644
--- a/cpu/cpu.ml
+++ b/cpu/cpu.ml
@@ -17,6 +17,7 @@ let cpu_ram ra we wa d =
         0x8000 to 0xFFFF is RAM *)
     let read_data = zeroes 8 in
 
+    (* ROM chip *)
     let ra_hi1 = ra ** 15 in
     let ra_lo1 = ra % (0, 14) in
     let ra_hi2 = ra ** 14 in
@@ -25,7 +26,7 @@ let cpu_ram ra we wa d =
     let rd_rom = rom "ROM0" 14 8 ra_lo2 in
     let read_data = mux read_rom read_data rd_rom in
 
-
+    (* RAM chip *)
     let read_ram = ra_hi1 in
     let wa_hi1 = wa ** 15 in
     let wa_lo1 = wa % (0, 14) in
@@ -33,6 +34,7 @@ let cpu_ram ra we wa d =
     let rd_ram = ram 15 8 ra_lo1 we_ram wa_lo1 d in
     let read_data = mux read_ram read_data rd_ram in
 
+    (* MMIO *)
     let read_tick = eq_c 16 ra 0x4000 in
     let next_tick, save_next_tick = loop 8 in
     let tick = nadder 8 (reg 8 next_tick) (get "tick" ++ zeroes 7) in
diff --git a/cpu/netlist_gen.ml b/cpu/netlist_gen.ml
index 1aad452..016c595 100644
--- a/cpu/netlist_gen.ml
+++ b/cpu/netlist_gen.ml
@@ -16,9 +16,8 @@ let add p id eq size =
     assert (not (Env.mem id p.p_vars) 
         || (Env.find id p.p_vars = size));
     assert (not (List.mem_assoc id p.p_eqs));
-    {   p_eqs = (id, eq)::p.p_eqs;
-        p_inputs = p.p_inputs;
-        p_outputs = p.p_outputs;
+    {   p with
+        p_eqs = (id, eq)::p.p_eqs;
         p_vars = Env.add id size p.p_vars }
 
 let get id =
@@ -195,9 +194,7 @@ let program entries outputs =
                 p, outputs)
         (p, []) outputs
     in
-    {   p_inputs = p.p_inputs;
-        p_eqs = p.p_eqs;
-        p_vars = p.p_vars;
+    {   p with
         p_outputs = List.rev outputs }
 
 
diff --git a/cpu/netlist_gen.mli b/cpu/netlist_gen.mli
index 280ee8c..67d4774 100644
--- a/cpu/netlist_gen.mli
+++ b/cpu/netlist_gen.mli
@@ -2,8 +2,6 @@ type t
 
 val print : out_channel -> Netlist_ast.program -> unit
 
-val id : string -> Netlist_ast.ident
-
 val get : Netlist_ast.ident -> t
 val loop : int -> (t * (t -> t))