Avalon MM FIFO

They're all in the same document. Click around or download the pdf: https://www.intel.com/content/www/us/en/docs/programmable/683130/24-1/interface-signals-02827.html

And I already said that when you read the readdata signal, depending on the address you access, the particular bit corresponds to the full, empty, etc. flags you mention as described in table 271. There aren't dedicated signals for these flags if that is what you are asking.

And again, the general function of each signal (readdata, writedata, read, write, address, etc.) is governed by the Avalon standard described in the Avalon spec I linked to.