Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!usc!apple!portal!cup.portal.com!mmm From: mmm@cup.portal.com (Mark Robert Thorson) Newsgroups: comp.arch Subject: Re: Beating pinout by voltage domain multiplexing Message-ID: <31906@cup.portal.com> Date: 20 Jul 90 04:24:28 GMT References: Organization: The Portal System (TM) Lines: 9 The limiting factor on pin driver bandwidth is what analog engineers call "slew rate", i.e. how fast you can change the voltage on a pin per unit time. Note that in your scheme, the transition time is different for 0 to 1 vs. 0 to 2 or 0 to 3. If you have an 8-bit integer bus, represented by four wires, the fastest you can sample the bus is the slowest transition between states, i.e. 0 to 3. Now if you were talking about multiplexing a binary voltage change with a binary current change, that might work.