Avago Technologies LSI53C896 - Manual (Page 91)

3-3
Version 3.3 Copyright © 1998–2003 by LSI Logic Corporation. All rights reserved.
There are five signal type definitions:
I Input, a standard input-only signal.
O Output, a standard output driver (typically a Totem Pole Output).
I/O Input and output (bidirectional).
T/S 3-state, a bidirectional, 3-state input/output signal.
S/T/S Sustained 3-state, an active LOW 3-state signal owned and driven by
one and only one agent at a time.