help with microcontroller

[sss]

hello guys.
i wanted to tweek my bike ,so i got a set of gauges from the newest model. i didnt check before buying , so apparently this new gauge is getting all the important signals (speed , temp etc) on a single wire - serial data from the main engine control unit.
inside there is nec 8bit microcontroller 78063 (a) series .
just wanted to know , if its 8 bit microcontroller , does it mean that it recieves data 8 bit at a time?
and , if the input is only one wire (except grount) , how can the input data be synchronized with the microcontroller pulse this way?
heres the datasheet for the mcu
http://www.eu.necel.com/_pdf/U10335EJ2V0DS00.PDF
any help would be great

[I_Forgot]

No. An 8 bit microcontroller has a nominal register width of 8 bits. That does not mean that the signal being received is in 8 bit chunks. The signaling protocol between the engine computer and your gauge could be set up in a zillion different ways. The data is probably packaged in some combination of address, synchronization, and error correction.

I_F

[sss]

thanks allot!
oh ,well , i guess i will need to make my own counters and connect them to the 7 seg lcd displays and tachometer