I would like to ask, how can I write vectors in VHDL.
Below I have written the VHDL code in Integers, But I am having
difficulties in writing it as Vectors?
The equation I am working with to find the correct answer from Waveform
is:
FX= A0 +A1x +A2^x2 +A3^x3
ENTITY Polynomial1 IS
PORT ( clk, res : IN BIT;
ai, x : IN INTEGER:=0;
fx : OUT INTEGER:=0);
END Polynomial1;
ARCHITECTURE bhv OF Polynomial1 IS SIGNAL reg : INTEGER:=0;
BEGIN
PROCESS
BEGIN
WAIT UNTIL (clk'EVENT AND clk = '1');
IF res = '1' THEN reg <= 0;
ELSE reg <= x * (ai + reg);
END IF;
END PROCESS;
fx <= reg + ai;
END bhv;

I have had a go at Vectors with assumable bits:
ENTITY Polynomial1 IS
PORT ( clk, reset : IN STD_LOGIC;
a0, a1, a2, a3 : IN STD_LOGIC_VECTOR(2 DOWNTO 0);
x : IN STD_LOGIC_VECTOR (1 DOWNTO 0);
fx: OUT STD_LOGIC_VECTOR(8 DOWNTO 0)) ;
END Polynomial1;

I would like to apologies if i have made any format mistakes.