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Altera_Forum's avatar
Altera_Forum
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13 years ago

Case?

Can anyone help me shorten this if into a case ?

Is it smart? 

   -- Signaltap end
   PROCESS (CLOCK_50, KEY(0), KEY(1))
   BEGIN
      IF (CLOCK_50'EVENT AND CLOCK_50 = '1') THEN -- Trigger Condition
        
            IF KEY(0) = '0' AND  KEY(1) = '0' THEN
                q <= q;
            ELSE 
                IF KEY(0) = '1' AND  KEY(1) = '0' THEN
                    q <= '1'; -- Set
                ELSE
                    IF KEY(0) = '0' AND  KEY(1) = '1' THEN
                        q <= '0'; -- Reset
                    END IF;
                END IF;
            END IF;
      END IF;
   END PROCESS;

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    PROCESS (CLOCK_50)

    BEGIN

    IF (CLOCK_50'EVENT AND CLOCK_50 = '1') THEN -- Trigger Condition

    IF KEY(0) = '1' AND KEY(1) = '0' THEN

    q <= '1'; -- Set

    ELSIF KEY(0) = '0' AND KEY(1) = '1' THEN

    q <= '0'; -- Reset

    ELSE

    null;

    END IF;

    END IF;

    END PROCESS;
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    --- Quote Start ---

    Can anyone help me shorten this if into a case ?

    --- Quote End --- 

    PROCESS (CLOCK_50)  -- Key() should not be in the list  , KEY(0), KEY(1))
  variable KeyCode: natural range 0 to 3;
BEGIN
IF (CLOCK_50'EVENT AND CLOCK_50 = '1') THEN -- Trigger Condition
    -- Assuming that Key is a std_logic_vector and possibly longer than
    -- just two bits.
    KeyCode := to_integer(unsigned(Key(1 downto 0));
    case KeyCode is
        when 1 => q <= '1'; -- Set
        when 2 => q <= '0'; -- Reset
        when others => null;
    end case;
END IF;
END PROCESS;

    --- Quote Start ---

    Is it smart?

    --- Quote End ---

    No it is not smart...people can be smart, but 'it' cannot.

    Kevin Jennings