library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith;use ieee.std_logic_signed.all;use ieee.numeric_std.all;entity control is       port(clk        :in std_logic;            rst        :in std_logic;            instr      :in std_logic_vector(15 downto 0);                re         :out std_logic;                                  wr         :out std_logic;                                  muxalu1_c  :out std_logic;                                   muxalu2_c  :out std_logic;                                   alu_c      :out std_logic_vector(1 downto 0);                muxwrd_c   :out std_logic_vector(1 downto 0);                en_ir      :out std_logic;                                   en_wr      :out std_logic;                                   en_r1      :out std_logic;                                   en_r2      :out std_logic;                                   wra        :out std_logic_vector(1 downto 0);               rra1       :out std_logic_vector(1 downto 0);                rra2       :out std_logic_vector(1 downto 0);               comp_c     :out std_logic_vector(2 downto 0);                pcalu_c    :out std_logic_vector(2 downto 0);                jmp_imm    :out std_logic_vector(11 downto 0);               comp_imm   :out std_logic_vector(7 downto 0);                rdm_imm    :out std_logic_vector(9 downto 0);                muxwrd_mov :out std_logic                                    );end entity control;architecture one of control is       subtype state_type is std_logic_vector(1 downto 0);       constant FETCH    :state_type:="00";       constant DECODE   :state_type:="01";       constant EXECUTE  :state_type:="10";              signal cur_state  :state_type;       signal next_state :state_type;       begin    state_comb:process(cur_state,rst)                 begin                   if(rst='1') then                      next_state<=FETCH;                   else                    CASE cur_state is                      WHEN FETCH=>                           next_state<=DECODE;                      WHEN DECODE=>                           next_state<=EXECUTE;                      WHEN OTHERS=>                           next_state<=FETCH;                     end case;                   end if;               end process state_comb;                                    state_sync:process(rst,clk)                 begin                   if (rst='1') then                      cur_state<=FETCH;                   ELSIF(rising_edge(clk)) then                      cur_state<=next_state;                   end if;               end process state_sync;                       BODY_MAIN:PROCESS(cur_state,instr,rst)                  variable rs,rt,rd :std_logic_vector(1 downto 0);                  variable temp:std_logic_vector(3 downto 0);                  --- variable jmp_imm  :std_logic_vector(11 downto 0);                  ---variable rdm_imm  :std_logic_vector(9 downto 0);                  ---variable comp_imm :std_logic_vector(7 downto 0);              begin                  rs      :=instr(11 downto 10);                  rt      :=instr(9 downto 8);                  rd      :=instr(7 downto 6);                  temp    :=instr(15 downto 12);                  ----jmp_imm :=instr(11 downto 0);                  ----rdm_imm :=instr(9 downto 0);                  ----comp_imm:=instr(7 downto 0);                                                    if (rst='1') then                     re         <='0';                     wr         <='0';                     muxalu1_c  <='0';                                        muxalu2_c  <='0';                                           alu_c      <="00";                         muxwrd_c   <="00";                     en_ir      <='0';                     en_wr      <='0';                     en_r1      <='0';                     en_r2      <='0';                                           --wra        <="00";                     rra1       <="00";                     rra2       <="00";                     comp_c     <="000";                                           pcalu_c    <=(others=>'0');                                          jmp_imm    <=(others=>'0');                     comp_imm   <=(others=>'0');                     rdm_imm    <=(others=>'0');                     muxwrd_mov <='0' ;                   else                   -- re<='0';                    --en_ir<='0';                                      case cur_state is                                        when FETCH =>                          re<='1';                          en_ir<='1';                          wr<='0';                          muxalu1_c<='0';                                             muxalu2_c<='0';                                                alu_c<="00";                              muxwrd_c<="11";                          en_wr<='0';                          en_r1<='0';                          en_r2<='0';                                                --wra<="00";                          rra1<="00";                          rra2<="00";                          comp_c<="000";                                                pcalu_c<=(others=>'0');                                               jmp_imm<=(others=>'0');                          comp_imm<=(others=>'0');                          rdm_imm<=(others=>'0');                          muxwrd_mov<='0' ;                                                when DECODE =>                           case temp is                           when "0001"=>                          --IF((instr(15 downto 12)="0001")or (instr(15 downto 12)="0010")                           --      or(instr(15 downto 12)="0011")) then                           -----and,or,xor                           alu_c<=instr(13 downto 12);                           rra1<=instr(11 downto 10);                           en_r1<='1';                           rra2<=instr(9 downto 8);                           en_r2<='1';                           --en_wr<='0';                           en_ir<='0';                           en_wr<='0';                           re<='0';                           wra<=instr(7 downto 6);                           muxalu1_c<='1';                           muxalu2_c<='1';                           muxwrd_c<="11";                           pcalu_c<="100" ;                           when "0010"=>                          --IF((instr(15 downto 12)="0001")or (instr(15 downto 12)="0010")                           --      or(instr(15 downto 12)="0011")) then                           -----and,or,xor                           alu_c<=instr(13 downto 12);                           rra1<=instr(11 downto 10);                           en_r1<='1';                           rra2<=instr(9 downto 8);                           en_r2<='1';                           --en_wr<='0';                           en_ir<='0';                           en_wr<='0';                           re<='0';                           wra<=instr(7 downto 6);                           muxalu1_c<='1';                           muxalu2_c<='1';                           muxwrd_c<="11";                           pcalu_c<="100" ;                                                      --end if;                           when "0011"=>                          --IF((instr(15 downto 12)="0001")or (instr(15 downto 12)="0010")                           --      or(instr(15 downto 12)="0011")) then                           -----and,or,xor                           alu_c<=instr(13 downto 12);                           rra1<=instr(11 downto 10);                           en_r1<='1';                           rra2<=instr(9 downto 8);                           en_r2<='1';                           en_wr<='0';                           en_ir<='0';                           re<='0';                           wra<=instr(7 downto 6);                           muxalu1_c<='1';                           muxalu2_c<='1';                           muxwrd_c<="11";                           pcalu_c<="100" ;                                                      --end if;                                                       when "0100"=>                         -- if(instr(15 downto 12)="0100") then                            ----mov                            re<='0';                            en_ir<='0';                            en_r1<='0';                            en_r2<='0';                               en_wr<='1';                            wra<=rs;                            muxwrd_c<="01";                            muxwrd_mov<=instr(0);                            pcalu_c<="100" ;                            --end if;                                                      when "0101" =>                          --if(instr(15 downto 12)="0101") then                             ----jmp                             pcalu_c<="010";                             en_ir<='0';                             re<='0';                             muxalu1_c<='0';