Error: The pin "data[5]" has multiple drivers due to the constant driver

I don't think they are using my data port at the same time.

LIBRARY IEEE;
    USE ieee.std_logic_1164.ALL;
ENTITY tri_buffer IS
 
        PORT(
        my_in  : IN STD_LOGIC_VECTOR(7 DOWNTO 0);
        sel    : IN STD_LOGIC;
        my_out : OUT STD_LOGIC_VECTOR(7 DOWNTO 0));
END tri_buffer;
ARCHITECTURE maxpld OF tri_buffer IS
BEGIN
 
 with sel select
 my_out <=
 
 my_in when '1',
 (others => 'Z') when others;
END maxpld;

library ieee;
use ieee.std_logic_1164.all;
 
entity normal_buffer is
 
 port(input: in std_logic_vector(7 downto 0);
   canWrite : in std_logic;
   clock : in std_logic;
   output: out std_logic_vector(7 downto 0));
end normal_buffer;
 
 
architecture logic of normal_buffer is
begin
 process
 begin
 
  wait until clock'event and clock = '1';
 
  if canWrite = '1' then
   output <= input;
  end if;
 
 end process;
end logic;

library ieee;
use ieee.std_logic_1164.all;
 
entity PC is
 port(output : out std_logic_vector(7 downto 0);
   i :in std_logic
  );
 
end PC;
 
architecture logic of PC is
--signal code : std_logic_vector(7 downto 0);
begin
 process(i)
 begin
 
  if i = '1' then
 
   output <= "00100000";
  end if;
 
 end process;
end logic;