scfifo-what is the problem

yes,kaz that is right but here i m trying to see that the output of the fifo is electrically and logically right,i tried meaningful fifo usage also like :

process(clk,reset_n)

begin

if reset_n=0 then

sender <="00000000";

elsif clk'event and clk='1' and full = '1' then

sender_out <= sender;

end if;

something like that but the result was same that i see the output pins' voltages very strange like impulses.

for example i write 0xa5 continuosuly,i look @ the pins of the output sender from oscilloscope and see the 1 bits and 0 bits @ right pins but 1 bits are electrically strange,that is they are not a step like function but like periodic impulses

is it something about the concurrency problem of the rdrequest and wrrequest signals?