Tristate-Master-Slave testbench description

May 13, 2005 5 Replies

Hi , I want to use the following component instantiation in my VHDL testbench:


entity tb_test is end tb_test;



architecture testbench of tb_test is


component test port ( Reset : in std_logic; Clk : in std_logic; Bidir_data : inout std_logic_vector(7 downto 0); Dir : in std_logic; Nxt : in std_logic; Stp : out std_logic ... ); end component;



signal t_Reset : std_logic; signal t_Clk : std_logic; signal t_Bidir_data : std_logic; signal t_Dir : std_logic; signal t_Nxt : std_logic; signal t_Stp : std_logic; .=2E.



signal t_tx_data : std_logic_vector(7 downto 0) signal t_drive_tx_data : std_logic;



signal t_rx_data : std_logic_vector(7 downto 0);


begin


uut : test port map ( Reset =3D> t_Reset, Clk =3D> t_Clk, Bidir_data =3D> t_Bidir_data, Dir =3D> t_Dir, Nxt =3D> t_Nxt, Stp =3D> t_Stp );



t_Bidir_data 'Z'); t_rx_data '0');



process begin -- Generate t_tx_data, t_drive_tx_data -- in this process end process;


end testbench;


My question : In the port map Bidir_data =3D> t_Bidir_data



an INOUT port of the unit under test is connected to a signal within the testbench.



Will the Tristate Description shown work ? (Which "direction does "t_Bidir_data" have ?) The testbench "t_tx_data" generation takes over the tristate bus master role.


Thank you for your help



Rgds Andr=E9



i guess u won't be able to simulate inout signals....simulator won't give error but the signal will be missing

Did you just try it? That would be the easy thing to do. Sure, it will work. There is normally no reason to tristate the receive data. Just do

t_rx_data

sps schrieb:

How can I solve this problem ? I must simulate inout signals ... Any alternative ?

Rgds Andr=E9

inout simulations work fine in simulator. just simulate your code. There is no direction for your "t_Bidir_data". its local to TB.

Yes, I tried it, and it works.

Thank you for your help :o)

Rgds Andr=E9 Duane Clark schrieb:

within

master

will

do

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