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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Problem about PIO

Here is my code:

# include <stdio.h># include <system.h># include "altera_avalon_pio_regs.h"# include "alt_types.h"

int main()

{

alt_u8 led = 0x1;

IOWR(0x00000800,0,led);

printf("Hello from Nios II!\n");

return 0;

}

Here, 0x00000800 comes from "#define PIO_0_BASE 0x00000800"

in system.h. But when I run the application in Modelsim. The out_port_from_the_pio_0 (2 bits) is zero all the time (I run it for 800us).

Anybody know why? Thank you very much!

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Have you set the direction? If it is defined as an output port only it might not be needed but give it a try. In NIOS 1 I found that the PIO component did as expected but in NIOS2 I have to tell the port to go into output or input mode as required.

    Victor Schutte

    www.zerksus.com