No, the registers are 16 bits wide, bits are labeled 0-15 (as usual) and you're interested in bit 8 (ie the 9th bit) which would then be the least significant bit in the high byte of the 16-bit Word. But really, look at it at as one 16bit value, convert the hex value you have to binary and compart at against the datasheet.

In fact, do that for "everything" and you might find something else that isn't right for your application - and you'll learn a lot.

/Henrik.