module Stack2 (     input clk,     output [16:0] rd,     input we,     input [2:0] delta,     input [16:0] wd );
     localparam WIDTH = 16;
     localparam DEPTH = 18;
     localparam BITS = (WIDTH * DEPTH);
     reg [(1)-1:0] do_move;
     always @(*) begin         headN = (we ? wd : tail[(16)-1:0]);
     end     reg [(288)-1:0] tailN;
     always @(*) begin         tailN = (move_dir ? {
21930, tail[(BITS)-1:16]}
 : {
tail[((BITS - 16))-1:0], head}
);
     end     always @(posedge clk) begin         if ((we | do_move)) begin             head <= headN;
         end         if (do_move) begin             tail <= tailN;
         end     end     always @(*) begin         rd = head;
     end endmodule  module J1a (     input clk,     input reset,     output [13:0] code_addr,     input [16:0] insn,     output LED1 );
     localparam WIDTH = 16;
     always @(*) pc_plus_1 = (pc + 1);
     reg [(1)-1:0] reboot;
     always @(*) begin         code_addr = pcN;
     end     reg [(16)-1:0] st1;
     reg [(2)-1:0] dspI;
     Stack2 dstack(.clk (clk),         .rd (st1),         .we (dstkW),         .wd (st0),         .delta (dspI));
     reg [(17)-1:0] minus;
     always @(*) minus = (({
1, !(st0)}
 + st1) + 1);
     always @(*) begin         if ((insn[15] == 0)) begin             st0N = insn;
             dstkW = 1;
             dspI = 2;
         end         else begin             case (insn[(15)-1:0])                 0: begin                     st0N = minus[(16)-1:0];
                     dstkW = 0;
                 end             endcase         end     end     always @(posedge clk) begin         if (reset) begin             reboot <= 1;
         end     end endmodule  module Main (     input clk,     output LED1,     output LED2,     output LED3,     output LED4 );
     always @(*) begin         LED2 = 0;
         LED3 = 0;
     end     always @(negedge clk) begin         insn <= code[code_addr];
     end endmodule