CBEn

[raggedstone] / dhwk / source / COMM_FSM.vhd

-- J.STELZNER\r
-- INFORMATIK-3 LABOR\r
-- 23.08.2006\r
-- File: COMM_FSM.VHD\r
\r
library ieee;\r
use ieee.std_logic_1164.all ;\r
\r
entity COMM_FSM is\r
	port\r
	(\r
	PCI_CLOCK		:in		std_logic; \r
	PCI_RSTn		:in		std_logic; \r
	IO_READ			:in		std_logic;\r
	IO_WRITE		:in		std_logic;\r
	CONF_READ		:in		std_logic;\r
	CONF_WRITE	:in		std_logic;\r
	DEVSELn			:in		std_logic;	\r
\r
	IO_RD_COM	:	out	std_logic;--> MUX_SEL(0)                                                      \r
	CF_RD_COM 	:out	std_logic; \r
	IO_WR_COM		:out	std_logic;     \r
	CF_WR_COM		:out	std_logic \r
	);\r
end entity COMM_FSM ;\r
\r
architecture COMM_FSM_DESIGN of COMM_FSM is\r
\r
\r
--**********************************************************\r
--***            COMMAND FSM CODIERUNG                   ***\r
--**********************************************************\r
--\r
--\r
--                                  			                   |--------- IO_RD_COM                                                    \r
--                                  			                   ||-------- CF_RD_COM   \r
--                 	  				                               |||------- IO_WR_COM   \r
--                     	                    			           ||||------ CF_WR_COM   \r
--                         	    			                       ||||     \r
	constant	ST_IDLE_COMM	:std_logic_vector (3 downto 0) := "0000" ;-- \r
	constant	ST_CONF_WRITE	:std_logic_vector (3 downto 0) := "0001" ;-- \r
	constant	ST_IO_WRITE		:std_logic_vector (3 downto 0) := "0010" ;-- \r
	constant	ST_CONF_READ	:std_logic_vector (3 downto 0) := "0100" ;-- \r
	constant	ST_IO_READ		:std_logic_vector (3 downto 0) := "1000" ;--\r
\r
	signal		COMM_STATE		:std_logic_vector (3 downto 0);\r
\r
--************************************************************\r
--***             FSM SPEICHER-AUTOMAT                     ***\r
--************************************************************\r
\r
	attribute syn_state_machine : boolean;\r
	attribute syn_state_machine of COMM_STATE : signal is false;\r
\r
begin\r
\r
--**********************************************************\r
--***           	 COMMAND FSM                        ***\r
--**********************************************************\r
\r
	process (PCI_CLOCK, PCI_RSTn) \r
	begin\r
		if	PCI_RSTn = '0'	then	COMM_STATE	<= "0000";\r
\r
		elsif (PCI_CLOCK'event and PCI_CLOCK = '1') then\r
 \r
			case COMM_STATE is\r
	\r
				when ST_IDLE_COMM => \r
					if		IO_READ				= '1' then							COMM_STATE <= ST_IO_READ;\r
\r
	  		  	elsif	CONF_READ		= '1' then							COMM_STATE <= ST_CONF_READ; \r
\r
						elsif	IO_WRITE		= '1' then							COMM_STATE <= ST_IO_WRITE;   \r
  \r
			    	elsif	CONF_WRITE	= '1' then							COMM_STATE <= ST_CONF_WRITE;     \r
\r
    		    else  																		COMM_STATE <= ST_IDLE_COMM;\r
					end if;						        \r
	\r
				when ST_IO_READ			=> if DEVSELn = '1' then	COMM_STATE <= ST_IDLE_COMM; end if;	 	\r
				when ST_CONF_READ		=> if DEVSELn = '1' then	COMM_STATE <= ST_IDLE_COMM; end if;	 	\r
				when ST_IO_WRITE		=> if DEVSELn = '1' then	COMM_STATE <= ST_IDLE_COMM; end if;	 	\r
				when ST_CONF_WRITE	=> if DEVSELn = '1' then	COMM_STATE <= ST_IDLE_COMM; end if;\r
	\r
				when others =>																COMM_STATE <= ST_IDLE_COMM; \r
\r
 			end case;		-- COMM_STATE    \r
		end if;				-- CLOCK   \r
	end process;		-- PROCESS\r
\r
	IO_RD_COM	<=	COMM_STATE(3);                                                     \r
	CF_RD_COM	<=	COMM_STATE(2);      \r
	IO_WR_COM	<=	COMM_STATE(1);      \r
	CF_WR_COM	<=	COMM_STATE(0);      \r
	\r
end architecture COMM_FSM_DESIGN ;\r
\r