headfile problems of Nios2,tks!

dearall:

i created a Nios2 project,add a c file and a head file to the project:

//altera_avalon_usb.h//

# ifndef __ALTERA_AVALON_USB_REGS_H__# define __ALTERA_AVALON_USB_REGS_H__

# include <io.h>

# define IORD_ALTERA_AVALON_USB_DATA(base) IORD(base, 0) # define IOWR_ALTERA_AVALON_USB_ADDR(base, data) IOWR(base, 0, data)# endif

///////////////////////////////////////////////////////////////////////////////////////////////////////////

//usbtest.c//

# include <stdio.h># include "altera_avalon_pio_regs.h"# include "altera_avalon_usb.h" ------------------------1# include "system.h" # include "excalibur.h" --------------------------------------2

main(void)

{

unsigned char i=0x46,j;

IOWR_ALTERA_AVALON_USB_ADDR(USB_BASE,i);

j=IORD_ALTERA_AVALON_USB_DATA(USB_BASE);

printf("the result is:");

printf("%c",j);

return(0);

}

when i compile the project , there are 2 errors :1 . 2

Kind Status Priority Description Resource In Folder Location

Error *** [obj/usbtest.o] Error 1 nios2_usb3

Kind Status Priority Description Resource In Folder Location

Error excalibur.h: No such file or directory usbtest.c nios2_usb3 line 5

i use altera cyclone board, and want to add usb(sl811hs) as user logic. it&#39;s very diffcult.

Now i plan to add usb as PIO . Can I do that ??