记录我的VHDL之路（三）

--/***************************************
--** THIS FILE FOR ADC_TLC2543 MODULE 
--** 有限状态机练习
--** BY YANGHUIDONG
--** DATE 20.1.2015  
--***************************************/
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;

ENTITY Full_FIR IS
PORT(
    RST:IN STD_LOGIC;
    Full_FIR:IN STD_LOGIC;
    CLK:IN STD_LOGIC;
    TLC2543_CLK:OUT STD_LOGIC;
    TLC2543_CS:OUT STD_LOGIC;
    TLC2543_OUT:OUT STD_LOGIC;
    --TLC2543_DATA_OUT:OUT STD_LOGIC_VECTOR(11 DOWNTO 0);
    TLC2543_IN:STD_LOGIC
    );
END Full_FIR;

ARCHITECTURE ONE OF Full_FIR IS
--AD SIGNAL
SIGNAL CNT:INTEGER RANGE 0 TO 24;
SIGNAL CLK1:STD_LOGIC;
SIGNAL TLC2543_ADDRESS:STD_LOGIC_VECTOR(15 DOWNTO 0);
SIGNAL TLC2543_TMP_DATA:STD_LOGIC_VECTOR(16 DOWNTO 0);
SIGNAL TLC2543_DATA_OUT:STD_LOGIC_VECTOR(11 DOWNTO 0);
BEGIN
--**********************************************
--AD Module
--分频进程
U1:PROCESS(CLK,RST)
BEGIN
    IF RST='0' THEN
        CNT<=0;
        CLK1<='1';
    ELSIF CLK'EVENT AND CLK='1' THEN
        IF CNT=10 THEN
            CNT<=0;
            CLK1<= NOT CLK1;
        ELSE
            CNT<=CNT+1;
        END IF; 
    END IF;
END PROCESS U1;

--ADC
U2:PROCESS(RST,CLK1)
VARIABLE NEXT_STATE:INTEGER RANGE 0 TO 5;
VARIABLE INDEX:INTEGER RANGE 0 TO 15;
VARIABLE DELAY:INTEGER RANGE 0 TO 10;
BEGIN
    IF RST='0' THEN
        NEXT_STATE:=0;
    ELSIF CLK1'EVENT AND CLK1='1' THEN
        IF Full_FIR='1' THEN
            CASE NEXT_STATE IS
                WHEN 0=>
                    TLC2543_CS<='0';
                    TLC2543_CLK<='0';
                    TLC2543_ADDRESS<="0000110000000000";
                    INDEX:=15;
                    NEXT_STATE:=1;
                WHEN 1=>
                    NEXT_STATE:=2;              
                WHEN 2=>
                    TLC2543_CLK<='0';
                    TLC2543_OUT<=TLC2543_ADDRESS(INDEX);
                    IF INDEX >0 THEN
                        INDEX:=INDEX-1;
                        NEXT_STATE:=3;
                    ELSE
                        INDEX:=15;
                        NEXT_STATE:=4;
                    END IF;
                WHEN 3=>
                    TLC2543_CLK<='1';
                    TLC2543_TMP_DATA(INDEX+1)<=TLC2543_IN;
                    NEXT_STATE:=2;
                WHEN 4=>TLC2543_CLK<='1';
                    TLC2543_TMP_DATA(0)<=TLC2543_IN;
                    TLC2543_DATA_OUT<=TLC2543_TMP_DATA(15 DOWNTO 4);
                    DELAY:=10;
                    NEXT_STATE:=5;
                WHEN 5=>
                    TLC2543_CLK<='0';
                    IF DELAY=0 THEN
                        TLC2543_CS<='1';
                        NEXT_STATE:=0;
                    ELSE
                        DELAY:=DELAY+1;
                        NEXT_STATE:=0;
                    END IF;         
            END CASE;
        ELSE
            NULL;
        END IF;
    END IF;
END PROCESS U2;