suma.vhd

adder 4 + 4 bits, for use with a Altera, and 2 displays 7 segments

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity suma is 
port 
(
k,m	: in	std_logic_vector (3 downto 0);	
x	: buffer std_logic_vector(4 downto 0);
s	: out	std_logic_vector (13 downto 0)
);	
end suma;

architecture pract of suma is 
begin
	x <= ('0'& k) + ('0'& m);
		--   abcdefg
		--   01234567...13
   	s <= 	"11111101111110" when (x = "00000") else
            "11111100110000" when (x = "00001") else 
            "11111101101101" when (x = "00010") else 
            "11111101111001" when (x = "00011") else 
            "11111100110011" when (x = "00100") else 
            "11111101011011" when (x = "00101") else 
            "11111101011111" when (x = "00110") else 
            "11111101110001" when (x = "00111") else    
            "11111101111111" when (x = "01000") else    
            "11111101111011" when (x = "01001") else 
			"01100001111110" when (x = "01010") else
            "01100000110000" when (x = "01011") else 
            "01100001101101" when (x = "01100") else 
            "01100001111001" when (x = "01101") else 
            "01100000110011" when (x = "01110") else 
            "01100001011011" when (x = "01111") else 
            "01100001011111" when (x = "10000") else 
            "01100001110001" when (x = "10001") else    
            "01100001111111" when (x = "10010") else    
            "01100001111011" when (x = "10011") else
			"11011011111110" when (x = "10100") else
            "11011010110000" when (x = "10101") else 
            "11011011101101" when (x = "10110") else 
            "11011011111001" when (x = "10111") else 
            "11011010110011" when (x = "11000") else 
            "11011011011011" when (x = "11001") else 
            "11011011011111" when (x = "11010") else 
            "11011011110001" when (x = "11011") else    
            "11011011111111" when (x = "11100") else    
            "11011011111011" when (x = "11101") else
			"11110011111110" when (x = "11110") else 
            "XXXXXXXXXXXXXX";
	
end pract;