array 2d in vhdl data transfer

[p11]

architecture Behavioral of rom is  


type memory is array (0 to 7) of STD_LOGIC_VECTOR (3 DOWNTO 0);
constant dat : memory := (x"3", x"2",x"4", x"0",x"6",x"0",x"5",x"0");

now if i want to assign the 1st value of the array then how to do it ??? i mean if i write


dout (3 downto 0)<=dat (0) ( 3 downto 0);


is it ok ???

 

[FvM]

It's O.K. if dout type is std_logic_vector and 3 downto 0 a valid subrange. If dout is defined as std_logic_vector (3 downto 0), you can simply write

dout <= dat(0);

 

[shaiko]

dout (3 downto 0)<=dat (0) [COLOR="#FF0000"](3 downto 0)[/COLOR] ;

It's fine.
But you can do without the part marked in red - this is because the array element is already defined as ( 3 downto 0 ) .
As long as the target of the assignment is of the same width as the source - there's no need to explicitly define the boundaries at the time of assignment.