MultiWii

why computeRC() is in top and why serialCom() is in annexCode() ??

I see computeRC() doing
>> rcData = rcSerial

and

I see serialCom() doing
>> rcSerial = data from serial

and my question is
why computeRC() is in
if ((int16_t)(currentTime - rcTime) > 0 ) { // 50Hz
this {}

and why serialCom() is in
annexCode()

please let me know why.. I can not sleep at all..TT