-------------- Original message ---------------------- From: Jon Smirl <[EMAIL PROTECTED]> > > Decoding I2C is normally done by software on the host. For a radeon there > is one io port/memory location that represents the clock and data of the > I2C stream. Software sits in a loop reading the data and decoding the I2C > protocol. Check out the Linux I2C drivers. AFAIK all you have to do is get > the I2C signal off the DVI connector and onto a visible IO address.
Hmmm, I think I2C is timing-sensitive. That must tie up the CPU full-time while it's uploading the data. But it's only for a few milliseconds during boot, so I suppose that's OK. > Note that there are two types of DDC, DDC1 and DDC2. DDC2 has replaced > DDC1 but there are monitors out there running DDC1. DDC1 and DDC2 are > different electrically. Yeah, the documents the URLs pointed to earlier said that. Well, if the BIOS implements the low-level protocol by bit-twiddling, it should be able to handle more than one timing format. So, it's only the external tool that would need an embedded microcontroller to perform I2C, when impersonating a monitor's EDID behavior. _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
