Custom Component Address Mapping

Yes, IORD always performs a 32bit access, even if you assign a char or a alt_u8 variable.

In case of a 8bit data bus, like yours, you'll always have 4 read accesses.

Note that this applies even if you use IORD_8DIRECT: this was reported somewhere in the forum as an Avalon bus anomaly.

Regarding address, the system interconnect fabric generated by sopc builder automatically selects the right slave when your system performs a memory access.

Then the slave must decode only addresses within its range.

You can refer to SOPC builder user guide for more detailed information.