[raggedstone] / dhwk / source / par_ser_con.vhd

-- $Id: par_ser_con.vhd,v 1.4 2007-03-11 13:23:11 sithglan Exp $

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity	PAR_SER_CON	is
        port
        (
                PCI_CLOCK		:in	std_logic; 
                RESET				:in	std_logic; 
                PSC_ENABLE			:in	std_logic; -- Parallel Serial Converter Enable
                SYNC_S_FIFO_EFn	                :in	std_logic; -- Empty Flag (low active)
                SPC_RDY_IN			:in	std_logic; -- Ready to receive data
                PAR_IN				:in	std_logic_vector(7 downto 0);
                SER_OUT				:out	std_logic; -- Serial Output
                S_FIFO_READn		        :out	std_logic  -- FIFO Read (low active)
        );			
end entity	PAR_SER_CON ;

architecture PAR_SER_CON_DESIGN	of PAR_SER_CON is

        constant STATE_END        :std_logic_vector(3 downto 0) := "0001";
        constant STATE_SEND       :std_logic_vector(3 downto 0) := "0010";
        constant STATE_SEND_BIT_0 :std_logic_vector(3 downto 0) := "0011";
        constant STATE_SEND_BIT_1 :std_logic_vector(3 downto 0) := "0100";
        constant STATE_SEND_BIT_2 :std_logic_vector(3 downto 0) := "0101";
        constant STATE_SEND_BIT_3 :std_logic_vector(3 downto 0) := "0110";
        constant STATE_SEND_BIT_4 :std_logic_vector(3 downto 0) := "0111";
        constant STATE_SEND_BIT_5 :std_logic_vector(3 downto 0) := "1000";
        constant STATE_SEND_BIT_6 :std_logic_vector(3 downto 0) := "1001";
        constant STATE_SEND_BIT_7 :std_logic_vector(3 downto 0) := "1010";

        signal COUNT     :std_logic_vector (3 downto 0);
        signal STATE     :std_logic_vector (3 downto 0); 
        signal DATUM     :std_logic_vector (7 downto 0);
        signal SYNC			 :std_logic; -- make SPC_RDY_IN stable

        attribute syn_state_machine:boolean;
        attribute syn_state_machine of STATE: signal is false;
        attribute syn_state_machine of COUNT: signal is false;
begin

        process(PCI_CLOCK)
        begin
                if (rising_edge(PCI_CLOCK)) then
                        if ("0000" < COUNT) then
                                COUNT <= COUNT - 1;
                        end if;

                        if (RESET = '1') then
                                STATE <= STATE_SEND;
                                COUNT <= "0000";
                                SER_OUT <= '0';
                                S_FIFO_READn <= '1';

                        elsif (PSC_ENABLE = '1') then
                                if (COUNT = "0000") then
                                        COUNT <= "0011";
                                        case STATE is
                                        when STATE_SEND =>
                                                if(SYNC = '1' and SYNC_S_FIFO_EFn = '1') then
                                                        SER_OUT <= '1';
                                                        S_FIFO_READn <= '0';
                                                        STATE <= STATE_SEND_BIT_0;
                                                end if;

                                        when STATE_SEND_BIT_0 =>
                                                DATUM     <= PAR_IN;
                                                S_FIFO_READn <= '1';
                                                SER_OUT <= PAR_IN(0); 
                                                STATE <= STATE_SEND_BIT_1;

                                        when STATE_SEND_BIT_1 =>
                                                SER_OUT <= DATUM(1); 
                                                STATE <= STATE_SEND_BIT_2;

                                        when STATE_SEND_BIT_2 =>
                                                SER_OUT <= DATUM(2); 
                                                STATE <= STATE_SEND_BIT_3;

                                        when STATE_SEND_BIT_3 =>
                                                SER_OUT <= DATUM(3); 
                                                STATE <= STATE_SEND_BIT_4;

                                        when STATE_SEND_BIT_4 =>
                                                SER_OUT <= DATUM(4); 
                                                STATE <= STATE_SEND_BIT_5;

                                        when STATE_SEND_BIT_5 =>
                                                SER_OUT <= DATUM(5); 
                                                STATE <= STATE_SEND_BIT_6;

                                        when STATE_SEND_BIT_6 =>
                                                SER_OUT <= DATUM(6); 
                                                STATE <= STATE_SEND_BIT_7;

                                        when STATE_SEND_BIT_7 =>
                                                SER_OUT <= DATUM(7); 
                                                STATE <= STATE_END;

                                        when STATE_END =>
                                                SER_OUT <= '0';
                                                STATE <= STATE_SEND;

                                        when others => STATE <= STATE_END;
                                        end case;

                                else
                                        S_FIFO_READn <= '1';
                                end if; -- COUNT
                        end if; -- RESET ... / PSC_ENABLE ...
                end if; -- PCI_CLOCK ...
        end process;

        process(PCI_CLOCK)
        begin
                if (rising_edge(PCI_CLOCK)) then
                        SYNC <= SPC_RDY_IN;
                end if;
        end process;

end architecture PAR_SER_CON_DESIGN;
Commit	Line	Data
e687cadb	1	-- $Id: par_ser_con.vhd,v 1.4 2007-03-11 13:23:11 sithglan Exp $
696ded12	2
	3	library ieee;
	4	use ieee.std_logic_1164.all;
	5	use ieee.std_logic_unsigned.all;
	6
	7	entity PAR_SER_CON is
2612d712	8	port
	9	(
	10	PCI_CLOCK :in std_logic;
	11	RESET :in std_logic;
	12	PSC_ENABLE :in std_logic; -- Parallel Serial Converter Enable
	13	SYNC_S_FIFO_EFn :in std_logic; -- Empty Flag (low active)
	14	SPC_RDY_IN :in std_logic; -- Ready to receive data
	15	PAR_IN :in std_logic_vector(7 downto 0);
	16	SER_OUT :out std_logic; -- Serial Output
	17	S_FIFO_READn :out std_logic -- FIFO Read (low active)
	18	);
696ded12	19	end entity PAR_SER_CON ;
	20
	21	architecture PAR_SER_CON_DESIGN of PAR_SER_CON is
	22
2612d712	23	constant STATE_END :std_logic_vector(3 downto 0) := "0001";
	24	constant STATE_SEND :std_logic_vector(3 downto 0) := "0010";
	25	constant STATE_SEND_BIT_0 :std_logic_vector(3 downto 0) := "0011";
	26	constant STATE_SEND_BIT_1 :std_logic_vector(3 downto 0) := "0100";
	27	constant STATE_SEND_BIT_2 :std_logic_vector(3 downto 0) := "0101";
	28	constant STATE_SEND_BIT_3 :std_logic_vector(3 downto 0) := "0110";
	29	constant STATE_SEND_BIT_4 :std_logic_vector(3 downto 0) := "0111";
	30	constant STATE_SEND_BIT_5 :std_logic_vector(3 downto 0) := "1000";
	31	constant STATE_SEND_BIT_6 :std_logic_vector(3 downto 0) := "1001";
	32	constant STATE_SEND_BIT_7 :std_logic_vector(3 downto 0) := "1010";
	33
	34	signal COUNT :std_logic_vector (3 downto 0);
	35	signal STATE :std_logic_vector (3 downto 0);
	36	signal DATUM :std_logic_vector (7 downto 0);
	37	signal SYNC :std_logic; -- make SPC_RDY_IN stable
	38
	39	attribute syn_state_machine:boolean;
	40	attribute syn_state_machine of STATE: signal is false;
	41	attribute syn_state_machine of COUNT: signal is false;
696ded12	42	begin
696ded12	43
2612d712	44	process(PCI_CLOCK)
2612d712	45	begin
e687cadb	46	if (rising_edge(PCI_CLOCK)) then
2612d712	47	if ("0000" < COUNT) then
	48	COUNT <= COUNT - 1;
	49	end if;
	50
	51	if (RESET = '1') then
	52	STATE <= STATE_SEND;
	53	COUNT <= "0000";
	54	SER_OUT <= '0';
	55	S_FIFO_READn <= '1';
	56
	57	elsif (PSC_ENABLE = '1') then
	58	if (COUNT = "0000") then
	59	COUNT <= "0011";
	60	case STATE is
	61	when STATE_SEND =>
	62	if(SYNC = '1' and SYNC_S_FIFO_EFn = '1') then
	63	SER_OUT <= '1';
	64	S_FIFO_READn <= '0';
	65	STATE <= STATE_SEND_BIT_0;
	66	end if;
	67
	68	when STATE_SEND_BIT_0 =>
696ded12	69	DATUM <= PAR_IN;
	70	S_FIFO_READn <= '1';
	71	SER_OUT <= PAR_IN(0);
	72	STATE <= STATE_SEND_BIT_1;
696ded12	73
2612d712	74	when STATE_SEND_BIT_1 =>
	75	SER_OUT <= DATUM(1);
	76	STATE <= STATE_SEND_BIT_2;
	77
	78	when STATE_SEND_BIT_2 =>
	79	SER_OUT <= DATUM(2);
	80	STATE <= STATE_SEND_BIT_3;
	81
	82	when STATE_SEND_BIT_3 =>
	83	SER_OUT <= DATUM(3);
	84	STATE <= STATE_SEND_BIT_4;
	85
	86	when STATE_SEND_BIT_4 =>
	87	SER_OUT <= DATUM(4);
	88	STATE <= STATE_SEND_BIT_5;
	89
	90	when STATE_SEND_BIT_5 =>
	91	SER_OUT <= DATUM(5);
	92	STATE <= STATE_SEND_BIT_6;
	93
	94	when STATE_SEND_BIT_6 =>
	95	SER_OUT <= DATUM(6);
	96	STATE <= STATE_SEND_BIT_7;
	97
	98	when STATE_SEND_BIT_7 =>
	99	SER_OUT <= DATUM(7);
	100	STATE <= STATE_END;
	101
	102	when STATE_END =>
	103	SER_OUT <= '0';
	104	STATE <= STATE_SEND;
	105
	106	when others => STATE <= STATE_END;
	107	end case;
	108
	109	else
	110	S_FIFO_READn <= '1';
	111	end if; -- COUNT
	112	end if; -- RESET ... / PSC_ENABLE ...
	113	end if; -- PCI_CLOCK ...
	114	end process;
	115
	116	process(PCI_CLOCK)
	117	begin
e687cadb	118	if (rising_edge(PCI_CLOCK)) then
2612d712	119	SYNC <= SPC_RDY_IN;
	120	end if;
	121	end process;
696ded12	122
696ded12	123	end architecture PAR_SER_CON_DESIGN;