I'm trying to talk to a SED1565 GLCD. Anyhoo... When I set up Synchronous Tx on a 128L everything is beautiful - signal comes on rising clock, etc. -- only one problemo: The data pin (TXD1) is *Hi*, and flips down to grnd and back up w/ signal. In looking at another chip (unknown; but was driving the SED1565 successfully) I see that it's data signal is at GROUND, and flips up to Vcc w/ signal. I don't see a setting for this in the UART regs... I understand that the way the 128's doing it may be corrct serial 'standard'.
I thought maybe the 128 has a register to "Invert pin" er something. (wishfull thinking - i know). I guess I could write an int on another pin which inverts whatever's on the Tx pin.. 'nuther thought was to use a different proto (like SPI 2W, etc.), as some of these look like they have polarity as settings...