implement loading into D1 too

decstates.v

@@ -13,6 +13,8 @@
 `define DEC_MEMACCESS       13      //  1[45]x[y]
 `define DEC_D0_EQ_5N        14      //  1B
 `define DEC_D0_EQ_5N_LOOP   15      //  1Bxxxxx (exec)
+`define DEC_D1_EQ_5N        16      //  1F
+`define DEC_D1_EQ_5N_LOOP   17      //  1Fxxxxx (exec)
 `define DEC_P_EQ_N          20      //  2n
 `define DEC_LC_LEN          21      //  3n...
 `define DEC_LC              22      //  3n[x]

opcodes/1Bnnnnn_D0_EQ_5n.v

@@ -1,27 +0,0 @@
-/******************************************************************************
- *1bnnnnn		DO=(5) nnnnn
- *
- *
- */ 
-
-`include "decstates.v"
-
-`DEC_D0_EQ_5N: begin
-    t_cnt <= 4;
-    t_ctr <= 1;
-    D0[3:0] <= nibble;    
-    decstate <= `DEC_D0_EQ_5N_LOOP;
-end
-`DEC_D0_EQ_5N_LOOP: begin
-    D0[t_ctr*4+:4] <= nibble;
-    if (t_ctr == t_cnt) begin
-        decstate <= `DEC_START;
-`ifdef SIM
-        $write("%5h D0=(5)\t%1h", inst_start_PC, nibble);
-        for(t_ctr = 0; t_ctr != t_cnt; t_ctr ++)
-            $write("%1h", D0[(t_cnt - t_ctr - 4'h1)*4+:4]);
-        $write("\n");
-`endif
-    end else 
-        t_ctr <= t_ctr + 1;
-end

opcodes/1[45]_memaccess_exec.v

@@ -1,75 +0,0 @@
-
-DECODE_MEMACCESS:
-    begin
-        if (runstate == `RUN_EXEC)
-            begin
-                t_ctr <= 0;
-                case (t_field)
-                    T_FIELD_B:
-                        begin
-                            t_offset <= 0;
-                            t_cnt <= 1;
-                        end
-                endcase
-                case (t_dir)
-                    T_DIR_OUT: runstate <= `WRITE_START;
-                    T_DIR_IN:  runstate <= `READ_START;
-                endcase
-    `ifdef SIM
-                $write("%5h ", saved_PC);
-                case (t_dir)
-                    T_DIR_OUT: $write("%s=%s\t", t_ptr?"DAT1":"DAT0", t_reg?"C":"A");
-                    T_DIR_IN:  $write("%s=%s\t", t_reg?"C":"A", t_ptr?"DAT1":"DAT0");
-                endcase
-                case (t_field)
-                    T_FIELD_P:   $display("P");
-                    T_FIELD_WP:  $display("WP");
-                    T_FIELD_XS:  $display("XS");
-                    T_FIELD_X:   $display("X");
-                    T_FIELD_S:   $display("S");
-                    T_FIELD_M:   $display("M");
-                    T_FIELD_B:   $display("B");
-                    T_FIELD_W:   $display("W");
-                    T_FIELD_LEN: $display("%d", t_cnt);
-                    T_FIELD_A:   $display("A");
-                endcase
-    `endif
-            end
-
-    // should be in the runstate case 
-
-        if (runstate == `WRITE_START)
-            begin
-    `ifdef SIM
-                $display("`WRITE_START    | ptr %s | dir %s | reg %s | field %h | off %h | ctr %h | cnt %h", 
-                            t_ptr?"D1":"D0", t_dir?"IN":"OUT", t_reg?"C":"A", t_field, t_field, t_offset, t_ctr, t_cnt);
-    `endif
-                bus_command <= `BUSCMD_LOAD_DP;
-                bus_address <= (~t_ptr)?D0:D1;
-                runstate <= `WRITE_STROBE;
-            end
-        if (runstate == `WRITE_STROBE)
-            begin
-    `ifdef SIM
-                $display("`WRITE_STROBE | ptr %s | dir %s | reg %s | field %h | off %h | ctr %h | cnt %h", 
-                            t_ptr?"D1":"D0", t_dir?"IN":"OUT", t_reg?"C":"A", t_field, t_offset, t_ctr, t_cnt);
-    `endif
-                bus_command <= `BUSCMD_DP_WRITE;
-                bus_nibble_in <= (~t_reg)?A[t_offset*4+:4]:C[t_offset*4+:4];
-                t_offset <= t_offset + 1;
-                t_ctr <= t_ctr + 1;
-                if (t_ctr == t_cnt)
-                    begin
-                        runstate <= `WRITE_DONE;
-                    end
-            end
-        if (runstate == `WRITE_DONE)
-            begin
-    `ifdef SIM
-                $display("`WRITE_DONE   | ptr %s | dir %s | reg %s | field %h | off %h | ctr %h | cnt %h", 
-                            t_ptr?"D1":"D0", t_dir?"IN":"OUT", t_reg?"C":"A", t_field, t_offset, t_ctr, t_cnt);
-    `endif
-                bus_command <= `BUSCMD_NOP;
-                runstate <= `NEXT_INSTR;
-            end
-    end

opcodes/1[BF]nnnnn_D[01]_EQ_5n.v

@@ -0,0 +1,41 @@
+/******************************************************************************
+ *1bnnnnn		DO=(5) nnnnn
+ *
+ *
+ */ 
+
+`include "decstates.v"
+
+`DEC_D0_EQ_5N, `DEC_D1_EQ_5N: begin
+    t_cnt <= 4;
+    t_ctr <= 1;
+    if (decstate == `DEC_D0_EQ_5N) begin
+        D0[3:0] <= nibble;    
+        decstate <= `DEC_D0_EQ_5N_LOOP;
+    end else begin
+        D1[3:0] <= nibble;    
+        decstate <= `DEC_D1_EQ_5N_LOOP;
+    end
+end
+`DEC_D0_EQ_5N_LOOP, `DEC_D1_EQ_5N_LOOP: begin
+    
+    if (decstate == `DEC_D0_EQ_5N_LOOP) 
+        D0[t_ctr*4+:4] <= nibble;
+    else 
+        D1[t_ctr*4+:4] <= nibble;
+    
+    if (t_ctr == t_cnt) begin
+        decstate <= `DEC_START;
+`ifdef SIM
+        $write("%5h D%b=(5)\t%1h", inst_start_PC, (decstate == `DEC_D0_EQ_5N_LOOP), nibble);
+        for(t_ctr = 0; t_ctr != t_cnt; t_ctr ++)
+            $write("%1h", 
+                (decstate == `DEC_D0_EQ_5N_LOOP)?
+                    D0[(t_cnt - t_ctr - 4'h1)*4+:4]:
+                    D1[(t_cnt - t_ctr - 4'h1)*4+:4]
+                );
+        $write("\n");
+`endif
+    end else 
+        t_ctr <= t_ctr + 1;
+end

opcodes/1x.v

@@ -9,7 +9,8 @@
 `DEC_1X: begin
     case (nibble)
     4'h4: decstate <= `DEC_14X;
-    4'hb: decstate <= `DEC_D0_EQ_5N;
+    4'hB: decstate <= `DEC_D0_EQ_5N;
+    4'hF: decstate <= `DEC_D1_EQ_5N;
     default: begin 
         $display("ERROR : DEC_1X");
         decode_error <= 1;    

saturn_core.v

@@ -379,7 +379,7 @@ always @(posedge dec_strobe) begin
 `include "opcodes/0x.v"
 `include "opcodes/1x.v"
 `include "opcodes/1[45]_memaccess.v"
-`include "opcodes/1Bnnnnn_D0_EQ_5n.v"
+`include "opcodes/1[BF]nnnnn_D[01]_EQ_5n.v"
 `include "opcodes/2n_P_EQ_n.v"
 `include "opcodes/3n[x...]_LC.v"
 `include "opcodes/6xxx_GOTO.v"