idt71v3556.vhd

来自「VHDL的ram和fifo model code 包含众多的厂家」· VHDL 代码 · 共 1,403 行 · 第 1/5 页

                        END IF;
                    WHEN write =>
                        state <= begin_wr;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        OBuf1 := (others => 'Z');
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                    WHEN burst =>
                        state <= burst_rd;
                        Burst_Cnt := Burst_Cnt + 1;
                        IF (Burst_Cnt = 4) THEN
                            Burst_Cnt := 0;
                        END IF;
                        offset := Burst_Seq(memstart)(Burst_Cnt);
                        MemAddr := startaddr + offset;
                        IF MemDataA(MemAddr) = -2 THEN
                            OBuf1(8 downto 0) := (others => 'U');
                        ELSIF MemDataA(MemAddr) = -1 THEN
                            OBuf1(8 downto 0) := (others => 'X');
                        ELSE
                            OBuf1(8 downto 0) := to_slv(MemDataA(MemAddr),9);
                        END IF;
                        IF MemDataB(MemAddr) = -2 THEN
                            OBuf1(17 downto 9) := (others => 'U');
                        ELSIF MemDataB(MemAddr) = -1 THEN
                            OBuf1(17 downto 9) := (others => 'X');
                        ELSE
                            OBuf1(17 downto 9) := to_slv(MemDataB(MemAddr),9);
                        END IF;
                        IF MemDataC(MemAddr) = -2 THEN
                            OBuf1(26 downto 18) := (others => 'U');
                        ELSIF MemDataC(MemAddr) = -1 THEN
                            OBuf1(26 downto 18) := (others => 'X');
                        ELSE
                            OBuf1(26 downto 18) := to_slv(MemDataC(MemAddr),9);
                        END IF;
                        IF MemDataD(MemAddr) = -2 THEN
                            OBuf1(35 downto 27) := (others => 'U');
                        ELSIF MemDataD(MemAddr) = -1 THEN
                            OBuf1(35 downto 27) := (others => 'X');
                        ELSE
                            OBuf1(35 downto 27) := to_slv(MemDataD(MemAddr),9);
                        END IF;
                 END CASE;

            WHEN begin_wr =>
                BWA2 := BWA1;
                BWB2 := BWB1;
                BWC2 := BWC1;
                BWD2 := BWD1;
                Burst_Cnt := 0;
                CASE command IS
                    WHEN ds =>
                        state <= desel;
                        OBuf1 := (others => 'Z');
                    WHEN read =>
                        state <= begin_rd;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        IF MemDataA(MemAddr) = -2 THEN
                            OBuf1(8 downto 0) := (others => 'U');
                        ELSIF MemDataA(MemAddr) = -1 THEN
                            OBuf1(8 downto 0) := (others => 'X');
                        ELSE
                            OBuf1(8 downto 0) := to_slv(MemDataA(MemAddr),9);
                        END IF;
                        IF MemDataB(MemAddr) = -2 THEN
                            OBuf1(17 downto 9) := (others => 'U');
                        ELSIF MemDataB(MemAddr) = -1 THEN
                            OBuf1(17 downto 9) := (others => 'X');
                        ELSE
                            OBuf1(17 downto 9) := to_slv(MemDataB(MemAddr),9);
                        END IF;
                        IF MemDataC(MemAddr) = -2 THEN
                            OBuf1(26 downto 18) := (others => 'U');
                        ELSIF MemDataC(MemAddr) = -1 THEN
                            OBuf1(26 downto 18) := (others => 'X');
                        ELSE
                            OBuf1(26 downto 18) := to_slv(MemDataC(MemAddr),9);
                        END IF;
                        IF MemDataD(MemAddr) = -2 THEN
                            OBuf1(35 downto 27) := (others => 'U');
                        ELSIF MemDataD(MemAddr) = -1 THEN
                            OBuf1(35 downto 27) := (others => 'X');
                        ELSE
                            OBuf1(35 downto 27) := to_slv(MemDataD(MemAddr),9);
                        END IF;
                    WHEN write =>
                        state <= begin_wr;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        OBuf1 := (others => 'Z');
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                    WHEN burst =>
                        state <= burst_wr;
                        Burst_Cnt := Burst_Cnt + 1;
                        IF (Burst_Cnt = 4) THEN
                            Burst_Cnt := 0;
                        END IF;
                        offset := Burst_Seq(memstart)(Burst_Cnt);
                        MemAddr := startaddr + offset;
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                 END CASE;

            WHEN burst_rd =>
                CASE command IS
                    WHEN ds =>
                        state <= desel;
                        OBuf1 := (others => 'Z');
                    WHEN read =>
                        state <= begin_rd;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        IF MemDataA(MemAddr) = -2 THEN
                            OBuf1(8 downto 0) := (others => 'U');
                        ELSIF MemDataA(MemAddr) = -1 THEN
                            OBuf1(8 downto 0) := (others => 'X');
                        ELSE
                            OBuf1(8 downto 0) := to_slv(MemDataA(MemAddr),9);
                        END IF;
                        IF MemDataB(MemAddr) = -2 THEN
                            OBuf1(17 downto 9) := (others => 'U');
                        ELSIF MemDataB(MemAddr) = -1 THEN
                            OBuf1(17 downto 9) := (others => 'X');
                        ELSE
                            OBuf1(17 downto 9) := to_slv(MemDataB(MemAddr),9);
                        END IF;
                        IF MemDataC(MemAddr) = -2 THEN
                            OBuf1(26 downto 18) := (others => 'U');
                        ELSIF MemDataC(MemAddr) = -1 THEN
                            OBuf1(26 downto 18) := (others => 'X');
                        ELSE
                            OBuf1(26 downto 18) := to_slv(MemDataC(MemAddr),9);
                        END IF;
                        IF MemDataD(MemAddr) = -2 THEN
                            OBuf1(35 downto 27) := (others => 'U');
                        ELSIF MemDataD(MemAddr) = -1 THEN
                            OBuf1(35 downto 27) := (others => 'X');
                        ELSE
                            OBuf1(35 downto 27) := to_slv(MemDataD(MemAddr),9);
                        END IF;
                    WHEN write =>
                        state <= begin_wr;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        OBuf1 := (others => 'Z');
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                    WHEN burst =>
                        Burst_Cnt := Burst_Cnt + 1;
                        IF (Burst_Cnt = 4) THEN
                            Burst_Cnt := 0;
                        END IF;
                        offset := Burst_Seq(memstart)(Burst_Cnt);
                        MemAddr := startaddr + offset;
                        IF MemDataA(MemAddr) = -2 THEN
                            OBuf1(8 downto 0) := (others => 'U');
                        ELSIF MemDataA(MemAddr) = -1 THEN
                            OBuf1(8 downto 0) := (others => 'X');
                        ELSE
                            OBuf1(8 downto 0) := to_slv(MemDataA(MemAddr),9);
                        END IF;
                        IF MemDataB(MemAddr) = -2 THEN
                            OBuf1(17 downto 9) := (others => 'U');
                        ELSIF MemDataB(MemAddr) = -1 THEN
                            OBuf1(17 downto 9) := (others => 'X');
                        ELSE
                            OBuf1(17 downto 9) := to_slv(MemDataB(MemAddr),9);
                        END IF;
                        IF MemDataC(MemAddr) = -2 THEN
                            OBuf1(26 downto 18) := (others => 'U');
                        ELSIF MemDataC(MemAddr) = -1 THEN
                            OBuf1(26 downto 18) := (others => 'X');
                        ELSE
                            OBuf1(26 downto 18) := to_slv(MemDataC(MemAddr),9);
                        END IF;
                        IF MemDataD(MemAddr) = -2 THEN
                            OBuf1(35 downto 27) := (others => 'U');
                        ELSIF MemDataD(MemAddr) = -1 THEN
                            OBuf1(35 downto 27) := (others => 'X');
                        ELSE
                            OBuf1(35 downto 27) := to_slv(MemDataD(MemAddr),9);
                        END IF;
                 END CASE;

            WHEN burst_wr =>
                CASE command IS
                    WHEN ds =>
                        state <= desel;
                        OBuf1 := (others => 'Z');
                    WHEN read =>
                        state <= begin_rd;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        IF MemDataA(MemAddr) = -2 THEN
                            OBuf1(8 downto 0) := (others => 'U');
                        ELSIF MemDataA(MemAddr) = -1 THEN
                            OBuf1(8 downto 0) := (others => 'X');
                        ELSE
                            OBuf1(8 downto 0) := to_slv(MemDataA(MemAddr),9);
                        END IF;
                        IF MemDataB(MemAddr) = -2 THEN
                            OBuf1(17 downto 9) := (others => 'U');
                        ELSIF MemDataB(MemAddr) = -1 THEN
                            OBuf1(17 downto 9) := (others => 'X');
                        ELSE
                            OBuf1(17 downto 9) := to_slv(MemDataB(MemAddr),9);
                        END IF;
                        IF MemDataC(MemAddr) = -2 THEN
                            OBuf1(26 downto 18) := (others => 'U');
                        ELSIF MemDataC(MemAddr) = -1 THEN
                            OBuf1(26 downto 18) := (others => 'X');
                        ELSE
                            OBuf1(26 downto 18) := to_slv(MemDataC(MemAddr),9);
                        END IF;
                        IF MemDataD(MemAddr) = -2 THEN
                            OBuf1(35 downto 27) := (others => 'U');
                        ELSIF MemDataD(MemAddr) = -1 THEN
                            OBuf1(35 downto 27) := (others => 'X');
                        ELSE
                            OBuf1(35 downto 27) := to_slv(MemDataD(MemAddr),9);
                        END IF;
                    WHEN write =>
                        state <= begin_wr;
                        MemAddr := to_nat(AddressIn);
                        startaddr := MemAddr;
                        memstart := to_nat(AddressIn(1 downto 0));
                        OBuf1 := (others => 'Z');
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                    WHEN burst =>
                        Burst_Cnt := Burst_Cnt + 1;
                        IF (Burst_Cnt = 4) THEN
                            Burst_Cnt := 0;
                        END IF;
                        offset := Burst_Seq(memstart)(Burst_Cnt);
                        MemAddr := startaddr + offset;
                        BWA1 := BWANIn;
                        BWB1 := BWBNIn;
                        BWC1 := BWCNIn;
                        BWD1 := BWDNIn;
                        wr1  := true;
                 END CASE;

        END CASE;

        IF (OENegIn = '0') THEN
            D_zd <= (others => 'Z'), OBuf2 AFTER 1 ns;
        END IF;

    END IF;

    --------------------------------------------------------------------
    -- File Read Section
    --------------------------------------------------------------------
    -- Reads hex data from file. Three characters per