Programming IO ports in NIOS II

Adding extra nios cpu won't magically generate extra IO pins!

Your best hope is to add external logic to multiplex/demultiplex the information, these days that would typically be done in a small fpga!

Thankyou for your suggestion.actually im a student and is interested in learning nios ii.so i thought of using it.

I know that the pio core provides upto 32 IO ports.But how can i access each one of them.im familiar with 8051 programming.can u help me with this.

PIO ports are memory mapped.

For a PIO input you check the bits corresponding to the input you want to test.

For a PIO output you change the bits.

Nios tools provide some macros to easily work with PIOs.

Say PIO_BASE is base address (assigned in sopc builder) of a 16 wide PIO output port;

this will set high outputs 2,5,6,7,8,12 of a 16

IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 0x10F2);

Similar for an input port. This will test if input 6 is high:

if (IORD_ALTERA_AVALON_PIO_DATA(PIO_BASE) & 0x0040) ....