Do I need one interfacing circuit to connect arduino serial port to tx/rx pins of blackfin srv camera ?
Yes, the blackfin uses 3v3 and the arduino is 5v so you need a level translator like the sort Sparkfun sells. However you might be able to get away with just a potential divider from the output of the arduino to the input of the blackfin with the input of the arduino connected directly to the blackfin.