Very simple question about PIO

Altera_Forum · ‎12-23-2005

typedef volatile struct

{

int np_piodata; // read/write, up to 32 bits

int np_piodirection; // write/readable, up to 32 bits, 1->output bit

int np_piointerruptmask; // write/readable, up to 32 bits, 1->enable interrupt

int np_pioedgecapture; // read, up to 32 bits, cleared by any write

} np_pio;

can you explain me how to use PIO register...for example if i want to read

a pio register... i do PIO->np_piodata..

Why does the function of " np_piodirection"

Altera_Forum · ‎12-24-2005

Hi,

in general if you want learn something about the peripherials, you might want to read "Altera Embeeded Peripherals Handbook" (n2cpu_nii5v3.pdf).

However you should use inl(...) for reading and outl(...) for writing the hardware register.

Accessing the hardware register with such a structure is a "Nios speciality".