We want to lay out our circuit board with this fuel gauge chip and an MSP430 so we could change from interfacing to it from HDQ initially to I2C later by changing the software in the MSP430. We would like to use the same MSP430 I/O line to run the HDQ line or the I2C clock line, just because the TI-provided software for these happen to use the same line.
My question is, if we are running in HDQ mode, is there any problem with the I2C clock line being wiggled, and conversely, if we are running in I2C mode, is there any problem with the HDQ line being wiggled? We could always put two zero ohm resistors in the layout and populate the one that would connect either the I2C clock or the HDQ line to the I/O line but it would be easier just to have them both connected.