Using nios2 system to let led display,but not success

[Altera_Forum]

Today, I had a nios2 system. Time in debugging, are all normal. However, when load in de2 board, not the results of operation. I would like to ask why, and how to resolve them.Thanks!:)  

Next is the test programme:  # include "system.h"# include "altera_avalon_pio_regs.h"# include "alt_types.h" int main (void) __attribute__ ((weak, alias ("alt_main"))); int alt_main (void) {  alt_u8 led = 0x2;  alt_u8 dir = 0;  volatile int i;    while (1)   {  if (led & 0x81)   {  dir = (dir ^ 0x1);  }  if (dir)   {  led = led >> 1;  }   else   {  led = led << 1;  }  IOWR_ALTERA_AVALON_PIO_DATA(LEDG_BASE, led);  i = 0;  while (i<200000)  i++;  }  return 0; }

[Altera_Forum]

there may have some problem with your hardware,eg down load was not successfully executed.but the sorftware tell ok.or,the hardware description is not the right one to your programme.that are all i guess

[Altera_Forum]

Thanks!It's helpfull!