tg68_fast.vhd

Mc68000 rtl code Simulation and Synthesis

								IF execOPC='1' THEN
									Regwrena <= '1';
								END IF;	
							ELSE
								IF decodeOPC='1' THEN
									ea_build <= '1';
								END IF;	
							END IF;	
							IF get_ea_now='1' THEN
								dest_areg <= '1';
								dest_hbits <= '1';
								regwrena <= '1';					
							END IF;
						ELSE
							trap_illegal <= '1';
							trap <= '1';
						END IF;
					ELSE								--chk	
						trap_illegal <= '1';
						trap <= '1';
						check_chk <= '1';
					END IF;
				ELSE
					CASE opcode(11 downto 9) IS
						WHEN "000"=>
							IF decodeOPC='1' THEN
								ea_build <= '1';
							END IF;
							IF opcode(7downto 6)="11" THEN					--move from SR
								set_exec_MOVESR <= '1';
								datatype <= "01";
								write_back <='1';							-- im 68000 wird auch erst gelesen
								IF execOPC='1' THEN
									IF endOPC='1' THEN
										Regwrena <= '1';
									END IF;
								END IF;
							ELSE											--negx
								use_XFlag <= '1';
								write_back <='1';
								set_exec_ADD <= '1';
								setaddsub <='0';
								IF execOPC='1' THEN
									source_lowbits <= '1';
									OP1out_zero <= '1';
									IF endOPC='1' THEN
										Regwrena <= '1';
									END IF;
								END IF;
							END IF;
						WHEN "001"=>
							IF opcode(7downto 6)="11" THEN					--move from CCR 68010
								trap_illegal <= '1';
								trap <= '1';
							ELSE											--clr
								IF decodeOPC='1' THEN
									ea_build <= '1';
								END IF;
								write_back <='1';
								set_exec_AND <= '1';
								IF execOPC='1' THEN
									OP1out_zero <= '1';
									IF endOPC='1' THEN
										Regwrena <= '1';
									END IF;
								END IF;
							END IF;
						WHEN "010"=>
							IF decodeOPC='1' THEN
								ea_build <= '1';
							END IF;
							IF opcode(7downto 6)="11" THEN					--move to CCR
								set_exec_MOVE <= '1';
								datatype <= "01";
								IF execOPC='1' THEN
									source_lowbits <= '1';
									to_SR <= '1';
								END IF;
							ELSE											--neg
								write_back <='1';
								set_exec_ADD <= '1';
								setaddsub <='0';
								IF execOPC='1' THEN
									source_lowbits <= '1';
									OP1out_zero <= '1';
									IF endOPC='1' THEN
										Regwrena <= '1';
									END IF;
								END IF;
							END IF;
						WHEN "011"=>										--not, move toSR
							IF opcode(7downto 6)="11" THEN					--move to SR
								IF SVmode='1' THEN
									IF decodeOPC='1' THEN
										ea_build <= '1';
									END IF;
									set_exec_MOVE <= '1';
									datatype <= "01";
									IF execOPC='1' THEN
										source_lowbits <= '1';
										to_SR <= '1';
									END IF;
								ELSE
									trap_priv <= '1';
									trap <= '1';
								END IF;
							ELSE											--not
								IF decodeOPC='1' THEN
									ea_build <= '1';
								END IF;
								write_back <='1';
								set_exec_EOR <= '1';
								IF execOPC='1' THEN
									OP2out_one <= '1';
									ea_data_OP1 <= '1';
									IF endOPC='1' THEN
										Regwrena <= '1';
									END IF;
								END IF;
							END IF;
						WHEN "100"|"110"=>
							IF opcode(7)='1' THEN			--movem, ext
								IF opcode(5 downto 3)="000" AND opcode(10)='0' THEN		--ext
									source_lowbits <= '1';
									IF decodeOPC='1' THEN
										set_exec_EXT <= '1';
										set_exec_move <= '1';
									END IF;
									IF opcode(6)='0' THEN
										datatype <= "01";		--WORD
									END IF;
									IF execOPC='1' THEN
										regwrena <= '1';	
									END IF;
								ELSE													--movem
--								IF opcode(11 downto 7)="10001" OR opcode(11 downto 7)="11001" THEN	--MOVEM
									ea_only <= '1';
									IF decodeOPC='1' THEN
										datatype <= "01";		--Word
										set_get_movem_mask <='1';
										set_get_extendedOPC <='1';
										
										IF opcode(5 downto 3)="010" OR opcode(5 downto 3)="011" OR opcode(5 downto 3)="100" THEN
											set_mem_rega <= '1';
											setstate <= "01";
											IF opcode(10)='0' THEN
												set_movem_busy <='1';
											ELSE	
												micronext <="00100010";
												microstep <='1';
											END IF;
										ELSE	
											ea_build <= '1';
										END IF;
										
									ELSE	
										IF opcode(6)='0' THEN
											datatype <= "01";		--Word
										END IF;
									END IF;
									IF execOPC='1' THEN
										IF opcode(5 downto 3)="100" OR opcode(5 downto 3)="011" THEN
											regwrena <= '1';
											save_memaddr <= '1';
										END IF;
									END IF;	
									IF get_ea_now='1' THEN
										set_movem_busy <= '1';
										IF opcode(10)='0' THEN
											setstate <="01";
										ELSE
											setstate <="10";
										END IF;
									END IF;
										IF opcode(5 downto 3)="100" THEN
											movem_presub <= '1';
										END IF;
										IF movem_addr='1' THEN
											IF opcode(10)='1' THEN
												regwrena <= '1';	
											END IF;
										END IF;	
										IF movem_busy='1' THEN
											IF opcode(10)='0' THEN
												setstate <="11";
											ELSE
												setstate <="10";
											END IF;
										END IF;	
								END IF;	
							ELSE
								IF opcode(10)='1' THEN						--MUL, DIV 68020
									trap_illegal <= '1';
									trap <= '1';
								ELSE							--pea, swap
									IF opcode(6)='1' THEN
										datatype <= "10";
										IF opcode(5 downto 3)="000" THEN 		--swap
											IF execOPC='1' THEN
												exec_swap <= '1';
												regwrena <= '1';	
											END IF;	
										ELSIF opcode(5 downto 3)="001" THEN 		--bkpt
										
										ELSE									--pea
											ea_only <= '1';
											IF decodeOPC='1' THEN
												ea_build <= '1';
											END IF;
											IF nextpass='1' AND prefix='0' THEN
												presub <= '1';
												setstackaddr <='1';
												set_mem_addsub <= '1';
												setstate <="11";
												microstep <='1';
											END IF;
											IF get_ea_now='1' THEN
												setstate <="01";
											END IF;
										END IF;	
									ELSE								--nbcd	
										IF decodeOPC='1' THEN		--nbcd
											ea_build <= '1';
										END IF;
										use_XFlag <= '1';
										write_back <='1';
										set_exec_ADD <= '1';
										set_exec_SBCD <= '1';
										IF execOPC='1' THEN 
											source_lowbits <= '1';
											OP1out_zero <= '1';
											IF endOPC='1' THEN
												Regwrena <= '1';
											END IF;
										END IF;
									END IF;
								END IF;
							END IF;
							
						WHEN "101"=>						--tst, tas
							IF decodeOPC='1' THEN
								ea_build <= '1';
							END IF;
							IF execOPC='1' THEN
								dest_hbits <= '1';				--for Flags
								source_lowbits <= '1';
		--						IF opcode(3)='1' THEN			--MC68020...
		--							source_areg <= '1';
		--						END IF;
							END IF;
							set_exec_MOVE <= '1';
							IF opcode(7 downto 6)="11" THEN		--tas
								set_exec_tas <= '1';
								write_back <= '1';
								datatype <= "00";				--Byte
								IF execOPC='1' AND endOPC='1' THEN
									regwrena <= '1';
								END IF;
							END IF;
--						WHEN "110"=>
						WHEN "111"=>					--4EXX
							IF opcode(7)='1' THEN		--jsr, jmp
								datatype <= "10";
								ea_only <= '1';
								IF nextpass='1' AND prefix='0' THEN
									presub <= '1';
									setstackaddr <='1';
									set_mem_addsub <= '1';
									setstate <="11";
									microstep <='1';
								END IF;
								IF decodeOPC='1' THEN
									ea_build <= '1';
								END IF;
								IF get_ea_now='1' THEN					--jsr
									IF opcode(6)='0' THEN
										setstate <="01";
									END IF;	
									ea_to_pc <= '1';
									IF opcode(5 downto 0)="111001" THEN
										writePC_add <= '1';
									ELSE
										writePC <= '1';
									END IF;
								END IF;
							ELSE						--
								CASE opcode(6 downto 0) IS
									WHEN "1000000"|"1000001"|"1000010"|"1000011"|"1000100"|"1000101"|"1000110"|"1000111"|		--trap
									     "1001000"|"1001001"|"1001010"|"1001011"|"1001100"|"1001101"|"1001110"|"1001111" =>		--trap
											trap_trap <='1';
											trap <= '1';
									WHEN "1010000"|"1010001"|"1010010"|"1010011"|"1010100"|"1010101"|"1010110"|"1010111" =>		--link
										datatype <= "10";
										IF decodeOPC='1' THEN
											micronext <="01000000";
											microstep <='1';
											set_exec_MOVE <= '1';						--f黵 displacement
											presub <= '1';
											setstackaddr <='1';
											set_mem_addsub <= '1';
											source_lowbits <= '1';
											source_areg <= '1';
										END IF;
										IF execOPC='1' THEN
											setstackaddr <='1';
											regwrena <= '1';
										END IF;
									
									WHEN "1011000"|"1011001"|"1011010"|"1011011"|"1011100"|"1011101"|"1011110"|"1011111" =>		--unlink
										datatype <= "10";
										IF decodeOPC='1' THEN
											setstate <= "10";
											set_mem_rega <= '1';
										ELSIF execOPC='1' THEN
											regwrena <= '1';
											exec_exg <= '1';
										ELSE	
											setstackaddr <='1';
											regwrena <= '1';
											get_ea_now <= '1';
											ea_only <= '1';
										END IF;
									
									WHEN "1100000"|"1100001"|"1100010"|"1100011"|"1100100"|"1100101"|"1100110"|"1100111" =>		--move An,USP
										IF SVmode='1' THEN
											no_Flags <= '1';
											to_USP <= '1';
											setstackaddr <= '1';
											source_lowbits <= '1';
											source_areg <= '1';
											set_exec_MOVE <= '1';
											datatype <= "10";
											IF execOPC='1' THEN
												regwrena <= '1';
											END IF;
										ELSE
											trap_priv <= '1';
											trap <= '1';
										END IF;
									WHEN "1101000"|"1101001"|"1101010"|"1101011"|"1101100"|"1101101"|"1101110"|"1101111" =>		--move USP,An
										IF SVmode='1' THEN
											no_Flags <= '1';
											from_USP <= '1';
											set_exec_MOVE <= '1';
											datatype <= "10";
											IF execOPC='1' THEN
												regwrena <= '1';
											END IF;
										ELSE
											trap_priv <= '1';
											trap <= '1';
										END IF;
									
									WHEN "1110000" =>					--reset
										IF SVmode='0' THEN
											trap_priv <= '1';
											trap <= '1';
										END IF;
										
									WHEN "1110001" =>					--nop
									
									WHEN "1110010" =>					--stop
										IF SVmode='0' THEN
											trap_priv <= '1';
											trap <= '1';
										ELSE
											IF decodeOPC='1' THEN
												setnextpass <= '1';
												set_directSR <= '1';
												set_stop <= '1';	
											END IF;
										END IF;
									
									WHEN "1110011" =>  									--rte
										IF SVmode='1' THEN
											IF decodeOPC='1' THEN
												datatype <= "01";
												setstate <= "10";
												postadd <= '1';
												setstackaddr <= '1';
												set_mem_rega <= '1';
												set_directSR <= '1';	
												microstep