Much better and clear explained in smart cock, b777 flight instrumments, chapter 10.50
Again, no EICAS system on B777, just an operational software ("function") located in each of a/c set of computers (AIMS).
B747-8 (repeat, out of memory, almost 2 yrs I don't touch any)have a different approach, no AIMS, just old 744 instruments with a new "interface" black box