Hi, I want to read a signal from a PIN.Everything ist fine I built it up in the SOPC Builder and declare a 8bit for Input. I chose 8Pins in Quartus and everything wotks fine. I can write Output to other Pins and it works also fine. But now I want to read a Pin if it 1 or 0. int in = IORD_ALTERA_AVALON_PIO_DATA(PIO_IN_BASE); printf("%i\n",in); Always they console print me 255. It doesen´t matter which PIN is on 3,3V from the Board. What I do wrong?? thx everybody for help.
Hi,maybe i ask my question in another way.What must i normally do when i want to read an input pin. In the SOPC Builder I chose an 8bit wide input. The Pins are correct connected in the Pin planner. The Quartus II Software runs correct and I have communication with the Nios II Prozessor. What must i normally do when i want to read an input pin now??
IT looks like you are doing everything right. Using signaltap you can check the actual value of the 8-bti signal that you provide to the PIO, and verify that it is the value you set the pins to.
And if your pins are defined as inputs with weak pull-ups (which is the default on most devices) then they will read 1 unless you connect them to ground. Connecting them to Vccio won't change their value.
You are right.I did everything right but the only problem is I did`t put them on Ground. Now it works thx a lot Daixiwen. (http://www.alteraforum.com/forum/member.php?find=lastposter&t=35770)Problem solved!