L298 current sensing... how does it work?

I am sorry for posting here, but it is related to my question. I have an l298 and i want to drive two dc motors (6V). I have not understand well what happens with the sense pins and if i should connect or not a resistor at those pins. By looking at the datasheet i saw that the sense node has a max value of 2 Volts, so if i would like to have, let's say 500mA maximum through my motor, if i put one resistor of 2V/500mA=4 Ohms that would work. But by some search i did, i got confused because i saw some examples where there was no resistor and the sense pins were grounded. If anyone could help... :confused: