[VHDL] Multiplexer Modeling | 멀티플렉서 모델링

Multiplexer Modeling

멀티플렉서 모델링

* Multiplexer (URL)

---

Dataflow Modeling with \(\texttt{with-select-when}\) Statement

-- Entity Body
ENTITY MUX_2x1 IS
    PORT ( w0, w1 : IN  bit;
                s : IN  bit;
                f : OUT bit );
END MUX_2x1;

-- Architecture Body
ARCHITECTURE Dataflow_with_select OF MUX_2x1 IS
    BEGIN
    WITH s SELECT
        f <= w0 WHEN '0',
             w1 WHEN OTHERS;
END Dataflow_with_else;

 

-- Entity Body
ENTITY mux_4x1 IS
    PORT ( w, x, y, z : IN  bit;
              mux_sel : IN  bit;
              mux_out : OUT bit );
END mux_4x1;

-- Architecture Body
ARCHITECTURE with_select_when_mux4x1 OF mux_4x1 IS
    BEGIN
    WITH mux_sel SELECT mux_out <= w WHEN "00",
                                   x WHEN "01",
                                   y WHEN "10",
                                   z WHEN OTHERS;
END with_select_when_mux4x1;

---

Dataflow Modeling with \(\texttt{when-else}\) Statement

-- Entity Body
ENTITY MUX_2x1 IS
    PORT ( w0, w1 : IN  bit;
                s : IN  bit;
                f : OUT bit );
END MUX_2x1;

-- Architecture Body
ARCHITECTURE Dataflow_when_else OF MUX_2x1 IS
BEGIN
    f <= w0 WHEN (s = '0') ELSE
         w1;
END Dataflow_when_else;

 

-- Entity Body
ENTITY mux_4x1 IS
    PORT ( w, x, y, z : IN  bit;
              mux_sel : IN  bit;
              mux_out : OUT bit );
END mux_4x1;

-- Architecture Body
ARCHITECTURE when_else_mux4x1 OF mux_4x1 IS
    BEGIN
    mux_out <= w WHEN (mux_sel = "00") ELSE
               x WHEN (mux_sel = "01") ELSE
               y WHEN (mux_sel = "10") ELSE
               z;
END when_else_mux4x1;

---

Behavioral Modeling with \(\texttt{if-else}\) Statement

-- Entity Body
ENTITY MUX_2x1 IS
    PORT ( w0, w1 : IN  bit;
                s : IN  bit;
                f : OUT bit );
END MUX_2x1;

-- Architecture Body
ARCHITECTURE Behavioral_if_else OF MUX_2x1 IS
BEGIN
    PROCESS(w0, w1, s)
        if (s = '0') then f <= w0;
        else f <= w1;
        end if;
    END PROCESS
END Behavioral_if_else;

 

-- Entity Body
ENTITY mux_4x1 IS
    PORT ( w, x, y, z : IN  bit;
              mux_sel : IN  bit;
              mux_out : OUT bit );
END mux_4x1;

-- Architecture Body
ARCHITECTURE if_else_mux4x1 OF mux_4x1 IS
    PROCESS (mux_sel, w, x, y, z)
    BEGIN
        IF    (mux_sel = "00") THEN mux_out <= w;
        ELSIF (mux_sel = "01") THEN mux_out <= x;
        ELSIF (mux_sel = "10") THEN mux_out <= y;
        ELSE                        mux_out <= z;
        END IF;
	END PROCESS;
END if_else_mux4x1;

---

Behavioral Modeling with \(\texttt{case-when}\) Statement

-- Entity Body
ENTITY MUX_2x1 IS
    PORT ( w0, w1 : IN  bit;
                s : IN  bit;
                f : OUT bit );
END MUX_2x1;

-- Architecture Body
ARCHITECTURE case_when_mux4x1 OF MUX_2x1 IS
BEGIN
    PROCESS(w0, w1, s)
    BEGIN
        CASE s IS
            WHEN '0'    => f <= w0;
            WHEN OTHERS => f <= w1;
        END CASE;
    END PROCESS
END case_when_mux4x1;

 

-- Entity Body
ENTITY mux_4x1 IS
    PORT ( w, x, y, z : IN  bit;
              mux_sel : IN  bit;
              mux_out : OUT bit );
END mux_4x1;

-- Architecture Body
ARCHITECTURE case_when_mux4x1 OF mux_4x1 IS
    PROCESS (mux_sel, w, x, y, z)
    BEGIN
        CASE mux_sel IS
            WHEN "00"   => mux_out <= w;
            WHEN "01"   => mux_out <= x;
            WHEN "10"   => mux_out <= y;
            WHEN OTHERS => mux_out <= z;
        END CASE;
	END PROCESS;
END case_when_mux4x1;

---

Configuration

CONFIGURATION CONF_A OF mux4x1 IS
    FOR with_select_when_mux4x1
    END FOR
END CONF_A;


CONFIGURATION CONF_B OF mux4x1 IS
    FOR when_else_mux4x1
    END FOR
END CONF_B;


CONFIGURATION CONF_C OF mux4x1 IS
    FOR if_else_mux4x1
    END FOR
END CONF_C;


CONFIGURATION CONF_D OF mux4x1 IS
    FOR case_when_mux4x1
    END FOR
END CONF_D;