Help with customer component in Qsys

Hey Altera people

I am not familiar this but I managed to create my peripheral (vhdl) and integrated it in my design. The problem is when I try to use by C program the result obviously is not what I expect!!

My entity is :

entity convo isport(
   clk : in std_logic;    wr_data : in std_logic_vector(31 downto 0);    cs : in std_logic;    wr_n : in std_logic;    addr : in std_logic;    clr_n : in std_logic;    rd : in std_logic;    rd_data : out std_logic_vector(31 downto 0));
end entity;
architecture behave of convo is
signal c1: std_logic_vector(31 downto 0);
begin
process(clk,wr_n)
variable rg: std_logic_vector(1 downto 0):="00";
variable c: natural;
begin
if (clk 'event and clk='1') then       
 if cs ='1' and wr_n = '0' then
for i in 0 to 15 loop 
c1(i+c)<=wr_data(i) xor rg(1);
c:=c+1;
c1(i+c)<=wr_data(i) xor rg(1) xor rg(0);
rg(1):=rg(0);
rg(0):=wr_data(i);
end loop;end if;end if;
end process;
rd_data<=c1; end;

My C code is

Code:

#include <stdio.h># include "system.h"# include "altera_avalon_convo.h"
int k;
int main(){  printf("Hello \n");
  IOWR(CONVO_0_BASE,0,0x10);
  k=IORD(CONVO_0_BASE,0);  
printf("%d\n",k);
  return 0; }

the console shows : Hello 16 (16=0x10 the input !!!)

your help is greatly appreciated