fifo7881.vhd

VHDL的ram和fifo model code 包含众多的厂家

   END IF ;

    ------------------------------------------------------------------------
    -- Set IR high after reset
    ------------------------------------------------------------------------

    IF ((WCLK_ipd'EVENT) AND (To_X01(WCLK_ipd) = '1') AND 
        (To_X01(RSNeg_ipd) = '1') AND (wordcounter = 0) AND 
        (rst = 0) AND (irflag = 0)) THEN

        wrtclkcount := wrtclkcount + 1 ;
        d_temp := TO_X01(d) ;

        CASE wrtclkcount IS
            WHEN 1 => NULL ;
            WHEN 2 =>
                flagstate := "0101" ;
                IRF_zd := flagstate(3) ;
                irflag := 1 ;
                wrtclkcount := 0 ;
            WHEN OTHERS => NULL ;
        END CASE ;

    END IF ;

    ------------------------------------------------------------------------
    -- Determine the status of the FIFO and assign the flag pins
    ------------------------------------------------------------------------

    ae_limit := ae_offset ;
    af_limit := 1024 - af_offset ;
    hf_limit := 512 ;
    f_limit := 1024 ;

    IF not Is_X(d) THEN

       CASE flagstate IS
           WHEN "X10X" => NULL ;
           WHEN "X100" => NULL ;
           WHEN "0100" => NULL ;
           WHEN "0101" =>
               IF ((wordcounter > ae_limit) AND (wordcounter <  hf_limit)) THEN
                   flagstate := "0001" ;
                   orflag := 0 ;
                   irflag := 1 ;

                   ORF_zd := flagstate(0) ;
                   AF_zd  := flagstate(1) ;
                   HF_zd  := flagstate(2) ;
                   IRF_zd := flagstate(3) ;
               END IF ;

           WHEN "0001" =>
               IF ((wordcounter > 0) AND (wordcounter <= ae_limit)) THEN
                   flagstate := "0101" ;
                   orflag := 0 ;
                   irflag := 1 ;

                   ORF_zd := flagstate(0) ;
                   AF_zd  := flagstate(1) ;
                   HF_zd  := flagstate(2) ;
                   IRF_zd := flagstate(3) ;
               END IF ;

               IF ((wordcounter >=  hf_limit) AND (wordcounter < af_limit)) THEN
                   flagstate := "0011" ;
                   orflag := 0 ;
                   irflag := 1 ;

                   ORF_zd := flagstate(0) ;
                   AF_zd  := flagstate(1) ;
                   HF_zd  := flagstate(2) ;
                   IRF_zd := flagstate(3) ;
               END IF ;

            WHEN "0011" =>
                IF ((wordcounter > ae_limit) AND (wordcounter <  hf_limit)) THEN
                    flagstate := "0001" ;
                    orflag := 0 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

                IF ((wordcounter >= af_limit) AND (wordcounter < f_limit )) THEN
                    flagstate := "0111" ;
                    orflag := 0 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "0111" =>
                IF ((wordcounter >=  hf_limit) AND (wordcounter < af_limit)) THEN
                    flagstate := "0011" ;
                    orflag := 0 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

                IF (wordcounter = f_limit ) THEN
                    flagstate := "0110" ;
                    orflag := 0 ;
                    irflag := 0 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "0110" => NULL ;

            WHEN "1101" =>
                -- IF (wordcounter = 0) THEN
                --     flagstate := "0101" ;
                --     orflag := 0 ;
                --     irflag := 1 ;

                --     ORF_zd := flagstate(0) ;
                --     AF_zd  := flagstate(1) ;
                --     HF_zd  := flagstate(2) ;
                --     IRF_zd := flagstate(3) ;
                -- END IF ;

                IF ((wordcounter > ae_limit) AND (wordcounter <  hf_limit)) THEN
                    flagstate := "1001" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "1001" =>
                IF ((wordcounter > 0) AND (wordcounter <= ae_limit)) THEN
                    flagstate := "1101" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

                IF ((wordcounter >=  hf_limit) AND (wordcounter < af_limit)) THEN
                    flagstate := "1011" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "1011" =>
                IF ((wordcounter > ae_limit) AND (wordcounter <  hf_limit)) THEN
                    flagstate := "1001" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

                IF ((wordcounter >= af_limit) AND (wordcounter < f_limit )) THEN
                    flagstate := "1111" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "1111" =>
                IF ((wordcounter >=  hf_limit) AND (wordcounter < af_limit)) THEN
                    flagstate := "1011" ;
                    orflag := 1 ;
                    irflag := 1 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

                IF (wordcounter = f_limit ) THEN
                    flagstate := "1110" ;
                    orflag := 1 ;
                    irflag := 0 ;

                    ORF_zd := flagstate(0) ;
                    AF_zd  := flagstate(1) ;
                    HF_zd  := flagstate(2) ;
                    IRF_zd := flagstate(3) ;
                END IF ;

            WHEN "1110" => NULL ;

            WHEN OTHERS =>
                flagstate := "XXXX" ;

                ORF_zd := flagstate(0) ;
                AF_zd := flagstate(1) ;
                HF_zd    := flagstate(2) ;
                IRF_zd := flagstate(3) ;

        END CASE ;

    END IF ;



        ------------------------------------------------------------------------
        -- Path Delay Section
        ------------------------------------------------------------------------
        VitalPathDelay01 (
            OutSignal       =>  ORF,
            OutSignalName   =>  "ORF",
            OutTemp         =>  ORF_zd,
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => RSNeg_ipd'LAST_EVENT,
                      PathDelay         => (0 ns, 0 ns),
                      PathCondition     => (RSNeg_ipd = '0') ),
                1 => (InputChangeTime   => RCLK_ipd'LAST_EVENT,
                      PathDelay         => tpd_RCLK_ORF,
                      PathCondition     => TRUE ) ),
            GlitchData      => ORF_GlitchData );

        VitalPathDelay01 (
            OutSignal       =>  IRF,
            OutSignalName   =>  "IRF",
            OutTemp         =>  IRF_zd,
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => RSNeg_ipd'LAST_EVENT,
                      PathDelay         => (0 ns, 0 ns),
                      PathCondition     => (RSNeg_ipd = '0') ),
                1 => (InputChangeTime   => WCLK_ipd'LAST_EVENT,
                      PathDelay         => tpd_WCLK_IRF,
                      PathCondition     => TRUE ) ),
            GlitchData      => IRF_GlitchData );

        VitalPathDelay01 (
            OutSignal       =>  AF,
            OutSignalName   =>  "AF",
            OutTemp         =>  AF_zd,
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => RSNeg_ipd'LAST_EVENT,
                      PathDelay         => tpd_RSNeg_AF,
                      PathCondition     => (RSNeg_ipd = '0') ),
                1 => (InputChangeTime   => RCLK_ipd'LAST_EVENT,
                      PathDelay         => tpd_RCLK_AF,
                      PathCondition     => TRUE ) ),
            GlitchData      => AF_GlitchData );

       VitalPathDelay01 (
            OutSignal       =>  HF,
            OutSignalName   =>  "HF",
            OutTemp         =>  HF_zd,
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => RSNeg_ipd'LAST_EVENT,
                      PathDelay         => tpd_RSNeg_HF,
                      PathCondition     => (RSNeg_ipd = '0') ),
                1 => (InputChangeTime   => RCLK_ipd'LAST_EVENT,
                      PathDelay         => tpd_RCLK_HF,
                      PathCondition     => TRUE ) ),
            GlitchData      => HF_GlitchData );
 
       VitalPathDelay01Z (
            OutSignal       =>  Q17,
            OutSignalName   =>  "Q17",
            OutTemp         =>  Q_zd(17),
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => OE_ipd'LAST_EVENT,
                      PathDelay         => tpd_OE_Q0,
                      PathCondition     => TRUE ),
                1 => (InputChangeTime   => RCLK_ipd'LAST_EVENT,
                      PathDelay         => tpd_RCLK_Q0,
                      PathCondition     => TRUE ) ),
            GlitchData      => Q_GlitchData );
 
       VitalPathDelay01Z (
            OutSignal       =>  Q16,
            OutSignalName   =>  "Q16",
            OutTemp         =>  Q_zd(16),
            XOn             => XOn,
            MsgOn           => MsgOn,
            Paths           => (
                0 => (InputChangeTime   => OE_ipd'LAST_EVENT,
                      PathDelay         => tpd_OE_Q0,