tg68_fast.vhd

Mc68000 rtl code Simulation and Synthesis

		micronext <= "00000001";
		setaddrlong <= '0';
		setnextpass <= '0';
		regdirectsource <= '0';
		setdisp <= '0';
		setdispbyte <= '0';
		setdispbrief <= '0';
		setbriefext <= '0';
		setgetbrief <= '0';
		longreaddirect <= '0';
		dest_areg <= '0';
		source_areg <= '0';
		data_is_source <= '0';
		write_back <= '0';
		setstackaddr <= '0';
		writePC <= '0';
		writePC_add <= '0';
		set_TG68_PC_dec <= '0';
		set_directPC <= '0';
		set_exec_ADD <= '0';
		set_exec_OR <= '0';
		set_exec_AND <= '0';
		set_exec_EOR <= '0';
		set_exec_MOVE <= '0';
		set_exec_MOVEQ <= '0';
		set_exec_MOVESR <= '0';
		set_exec_ADDQ <= '0';
		set_exec_CMP <= '0';
		set_exec_ROT <= '0';
		set_exec_EXT <= '0';
		set_exec_CPMAW <= '0';
		OP2out_one <= '0';
		ea_to_pc <= '0';
		ea_build <= '0';
		get_ea_now <= '0';
		rot_bits <= "XX";
		rot_nop <= '0';
		set_rot_cnt <= "000001";
		set_movem_busy <= '0';
		set_get_movem_mask <= '0';
		save_memaddr <= '0';
		set_mem_addsub <= '0';
		exec_exg <= '0';
		exec_swap <= '0';
		exec_Bits <= '0';
		set_get_bitnumber <= '0';
		dest_hbits <= '0';
		source_lowbits <= '0';
		set_mem_rega <= '0';
   		ea_data_OP1 <= '0';
		ea_only <= '0';
		set_direct_data <= '0';
		set_get_extendedOPC <= '0';
		set_exec_tas <= '0';
		OP1out_zero <= '0';
		use_XZFlag <= '0';
		use_XFlag <= '0';
		set_exec_ABCD <= '0';
		set_exec_SBCD <= '0';
		set_exec_MULU <= '0';
		set_exec_DIVU <= '0';
		set_exec_Scc <= '0';
		trap_illegal <='0';
		trap_priv <='0';
		trap_1010 <='0';
		trap_1111 <='0';
		trap_trap <='0';
		trap_trapv <= '0';
		trap <='0';
		set_vectoraddr <='0';
		writeSR <= '0';
		set_directSR <= '0';
		set_stop <= '0';
		from_SR <= '0';
		to_SR <= '0';
		from_USP <= '0';
		to_USP <= '0';
		illegal_write_mode <= '0';
		illegal_read_mode <= '0';
		illegal_byteaddr <= '0';
		no_Flags <= '0';
		set_PCmarker <= '0';
		use_SP <= '0';
		set_Z_error <= '0';

		check_movep <= '0';
		check_chk <= '0';

------------------------------------------------------------------------------
--Sourcepass
------------------------------------------------------------------------------		
		IF ea_only='0' AND get_ea_now='1' THEN
			setstate <= "10";
		END IF;
		
		IF ea_build='1' THEN
			CASE opcode(5 downto 3) IS		--source
				WHEN "010"|"011"|"100" =>						-- -(An)+
					get_ea_now <='1';
					setnextpass <= '1';
					IF opcode(4)='1' THEN
						set_mem_rega <= '1';
					ELSE
						set_mem_addsub <= '1';
					END IF;
					IF opcode(3)='1' THEN	--(An)+
						postadd <= '1';
						IF opcode(2 downto 0)="111" THEN
							use_SP <= '1';
						END IF;
					END IF;	 	
					IF opcode(5)='1' THEN	-- -(An)
						presub <= '1'; 					
						IF opcode(2 downto 0)="111" THEN
							use_SP <= '1';
						END IF;
					END IF;	 	
					IF opcode(4 downto 3)/="10" THEN
						regwrena <= '1';
					END IF; 	
				WHEN "101" =>				--(d16,An)
					microstep <='1';
					micronext <="00000110";
					setgetbrief <='1';
					set_mem_regA <= '1';
				WHEN "110" =>				--(d8,An,Xn)
					microstep <='1';
					micronext <="00001000";
					setgetbrief <='1';
					set_mem_regA <= '1';
				WHEN "111" =>
					CASE opcode(2 downto 0) IS
						WHEN "000" =>				--(xxxx).w
							micronext <="00000010";
							microstep <='1';
						WHEN "001" =>				--(xxxx).l
							longreaddirect <= '1';
							micronext <="00000010";
							microstep <='1';
						WHEN "010" =>				--(d16,PC)
							microstep <='1';
							micronext <="00000110";
							setgetbrief <= '1';
							set_PCmarker <= '1';
						WHEN "011" =>				--(d8,PC,Xn)
							microstep <='1';
							micronext <="00001000";
							setgetbrief <= '1';
							set_PCmarker <= '1';
						WHEN "100" =>				--#data
							setnextpass <= '1';
							set_direct_data <= '1';
							IF datatype="10" THEN
								longreaddirect <= '1';
							END IF;
						WHEN OTHERS => 
					END CASE;
				WHEN OTHERS => 
			END CASE;
		END IF;
------------------------------------------------------------------------------
--prepere opcode
------------------------------------------------------------------------------		
		CASE opcode(7 downto 6) IS
			WHEN "00" => datatype <= "00";		--Byte
			WHEN "01" => datatype <= "01";		--Word
			WHEN OTHERS => datatype <= "10";	--Long
		END CASE;
		
		IF execOPC='1' AND endOPC='0' AND exec_write_back='1' THEN
			setstate <="11";
		END IF;		
		
------------------------------------------------------------------------------
--test illegal mode
------------------------------------------------------------------------------	
		IF (opcode(5 downto 3)="111" AND opcode(2 downto 1)/="00") OR (opcode(5 downto 3)="001" AND datatype="00") THEN
			illegal_write_mode <= '1';
		END IF;
		IF (opcode(5 downto 2)="1111" AND opcode(1 downto 0)/="00") OR (opcode(5 downto 3)="001" AND datatype="00") THEN
			illegal_read_mode <= '1';
		END IF;
		IF opcode(5 downto 3)="001" AND datatype="00" THEN
			illegal_byteaddr <= '1';
		END IF;

	
		CASE opcode(15 downto 12) IS
-- 0000 ----------------------------------------------------------------------------		
			WHEN "0000" => 
			--hier muss noch MOVEP rein
			IF opcode(8)='1' AND opcode(5 downto 3)="001" THEN --movep
				trap_illegal <= '1';
				trap <= '1';
			ELSE
				IF opcode(8)='1' OR opcode(11 downto 8)="1000" THEN 				--Bits
					IF execOPC='1' AND get_extendedOPC='0' THEN
						IF opcode(7 downto 6)/="00" AND endOPC='1' THEN
							regwrena <= '1';
						END IF;
						exec_Bits <= '1';
						ea_data_OP1 <= '1';
					END IF;	
--					IF get_extendedOPC='1' THEN
--						datatype <= "01";			--Word
--					ELS
					IF opcode(5 downto 4)="00" THEN
						datatype <= "10";			--Long
					ELSE	
						datatype <= "00";			--Byte
						IF opcode(7 downto 6)/="00" THEN
							write_back <= '1';
						END IF;
					END IF;
					IF decodeOPC='1' THEN
						ea_build <= '1';
						IF opcode(8)='0' THEN
							IF opcode(5 downto 4)/="00" THEN	--Dn, An
								set_get_extendedOPC <= '1';
							END IF;
							set_get_bitnumber <= '1';
						END IF;
					END IF;
				ELSE								--andi, ...xxxi	
					IF opcode(11 downto 8)="0000" THEN	--ORI
						set_exec_OR <= '1';
					END IF;
					IF opcode(11 downto 8)="0010" THEN	--ANDI
						set_exec_AND <= '1';
					END IF;
					IF opcode(11 downto 8)="0100" OR opcode(11 downto 8)="0110" THEN	--SUBI, ADDI
						set_exec_ADD <= '1';
					END IF;
					IF opcode(11 downto 8)="1010" THEN	--EORI
						set_exec_EOR <= '1';
					END IF;
					IF opcode(11 downto 8)="1100" THEN	--CMPI
						set_exec_CMP <= '1';
					ELSIF trap='0' THEN	
						write_back <= '1';
					END IF;
					IF opcode(7)='0' AND opcode(5 downto 0)="111100" AND (set_exec_AND OR set_exec_OR OR set_exec_EOR)='1' THEN		--SR
--					IF opcode(7)='0' AND opcode(5 downto 0)="111100" AND (opcode(11 downto 8)="0010" OR opcode(11 downto 8)="0000" OR opcode(11 downto 8)="1010") THEN		--SR
						IF SVmode='0' AND opcode(6)='1' THEN  --SR
							trap_priv <= '1';
							trap <= '1';
						ELSE
							from_SR <= '1';
							to_SR <= '1';
							IF decodeOPC='1' THEN
								setnextpass <= '1';
								set_direct_data <= '1';
							END IF;
						END IF;
					ELSE
						IF decodeOPC='1' THEN
							IF opcode(11 downto 8)="0010" OR opcode(11 downto 8)="0000" OR opcode(11 downto 8)="0100"  	--ANDI, ORI, SUBI
							   OR opcode(11 downto 8)="0110" OR opcode(11 downto 8)="1010" OR opcode(11 downto 8)="1100" THEN	--ADDI, EORI, CMPI
	--						IF (set_exec_AND OR set_exec_OR OR set_exec_ADD  	--ANDI, ORI, SUBI
	--						   OR set_exec_EOR OR set_exec_CMP)='1' THEN	--ADDI, EORI, CMPI
								
								microstep <='1';
								micronext <="00101000";
								set_direct_data <= '1';
								IF datatype="10" THEN
									longreaddirect <= '1';
								END IF;
							END IF;
						END IF;						
							
						IF execOPC='1' THEN
							ea_data_OP1 <= '1';
							IF opcode(11 downto 8)/="1100" THEN	--CMPI 
								IF endOPC='1' THEN
									Regwrena <= '1';
								END IF;
							END IF;
							IF opcode(11 downto 8)="1100"  OR opcode(11 downto 8)="0100" THEN	--CMPI, SUBI
								setaddsub <= '0';
							END IF;
						END IF;		
					END IF;		
				END IF;		
			END IF;		
				
-- 0001, 0010, 0011 -----------------------------------------------------------------		
			WHEN "0001"|"0010"|"0011" =>				--move.b, move.l, move.w
				set_exec_MOVE <= '1';
				IF opcode(8 downto 6)="001" THEN	
					no_Flags <= '1';
				END IF;
				IF opcode(5 downto 4)="00" THEN	--Dn, An
					regdirectsource <= '1';
				END IF;
				CASE opcode(13 downto 12) IS
					WHEN "01" => datatype <= "00";		--Byte
					WHEN "10" => datatype <= "10";		--Long
					WHEN OTHERS => datatype <= "01";	--Word
				END CASE;
				source_lowbits <= '1';					-- Dn=>  An=>
				IF opcode(3)='1' THEN
					source_areg <= '1';
				END IF;
				IF getbrief='1' AND nextpass='1' THEN	-- =>(d16,An)  =>(d8,An,Xn)
					set_mem_rega <= '1';
				END IF;	
				
				IF execOPC='1' AND opcode(8 downto 7)="00" THEN
					Regwrena <= '1';
				END IF;	
				
				IF nextpass='1' OR execOPC='1' OR opcode(5 downto 4)="00" THEN	
					dest_hbits <= '1';
					IF opcode(8 downto 6)/="000" THEN
						dest_areg <= '1';
					END IF;
				END IF;

				IF decodeOPC='1' THEN 
					ea_build <= '1';
				END IF;
				
				IF prefix='0' AND (nextpass='1' OR (opcode(5 downto 4)="00" AND decodeOPC='1')) THEN	
					CASE opcode(8 downto 6) IS		--destination
--						WHEN "000" =>						--Dn
--						WHEN "001" =>						--An
						WHEN "010"|"011"|"100" =>					--destination -(an)+
							IF opcode(7)='1' THEN
								set_mem_rega <= '1';
							ELSE
								set_mem_addsub <= '1';
							END IF;
							IF opcode(6)='1' THEN	--(An)+
								postadd <= '1';
								IF opcode(11 downto 9)="111" THEN
									use_SP <= '1';
								END IF;
							END IF;	 	
							IF opcode(8)='1' THEN	-- -(An)
								presub <= '1'; 					
								IF opcode(11 downto 9)="111" THEN
									use_SP <= '1';
								END IF;
							END IF;	
							IF opcode(7 downto 6)/="10" THEN
								regwrena <= '1';
							END IF; 
							setstate <= "11";
							microstep <='1';		--nop
						WHEN "101" =>				--(d16,An)
							microstep <='1';
							micronext <="00001011";
							set_mem_regA <= '1';
							setgetbrief <= '1';
						WHEN "110" =>				--(d8,An,Xn)
							microstep <='1';
							micronext <="00001110";
							set_mem_regA <= '1';
							setgetbrief <= '1';
						WHEN "111" =>
							CASE opcode(11 downto 9) IS
								WHEN "000" =>				--(xxxx).w
									microstep <='1';
									micronext <="00000011";
								WHEN "001" =>				--(xxxx).l
									longreaddirect <= '1';
									microstep <='1';
									micronext <="00000011";
								WHEN OTHERS => 
							END CASE;
						WHEN OTHERS => 
					END CASE;
				END IF;	
-- 0100 ----------------------------------------------------------------------------		
			WHEN "0100" =>				--rts_group
				IF opcode(8)='1' THEN		--lea
					IF opcode(6)='1' THEN		--lea
						IF opcode(7)='1' THEN		
							ea_only <= '1';
							IF opcode(5 downto 3)="010" THEN  	--lea (Am),An
								set_exec_move <='1';
								no_Flags <='1';
								dest_areg <= '1';
								dest_hbits <= '1';
								source_lowbits <= '1';
								source_areg <= '1';