Wrong address range for custom IP in SOPC

Thank you all for your replies!

I have fully understood why i need 12bits of addressing in the SOPC to address my custom IP.

As said, my IP has 512words of 64bits each. So physically it needs 9 bits for addressing. These bits ARE provided by the SOPC.

NIOS uses dynamic addressing for avaon bus components, since NIOS is 32bits and the components connected to the bus might be 16,or 64 like my case or whatever. In order to make programmers lives easier, NIOS addresses bytes!

So 9bits out of the SOPC address line go to the physical address_port of my custom IP and the rest 3bits are picking up the bytes out of the 64bit word coming out on the avalon bus by my IP. 2^3=8 64bits=8x8bytes.

As I understand it NIOS presents the 9bit address on the custom IP address_port, then the 64bit word comes out and then using the extra 3 bits NIOS fetches the word in 8 cycles, 1byte each cycle.