fmod with negative decimal numbers error?

the result of fmod(-0.6, 0.01) is -0.01 is this an error?
Baud rate - negative value in TH?

My question is that once we get the value of 28,800 after dividing the crystal frequency (11.0592Hz) by 12 and then by 32, why we divide the value 0f 28,800 by a negative 3 (-3 = FD in HEX) in TH register...
Maximum Negative voltage to gpio pin

I am using lpc2378 .I use zener diode for one application.It gives -0.8v pulse for some time. can it damage the gpio pins. What is maximum negaive voltage which we can apply to gpio pin.
fmod with negative decimal numbers error?

the result of fmod(-0.6, 0.01) is -0.01 is this an error?
Baud rate - negative value in TH?

My question is that once we get the value of 28,800 after dividing the crystal frequency (11.0592Hz) by 12 and then by 32, why we divide the value 0f 28,800 by a negative 3 (-3 = FD in HEX) in TH register...