For each motor driver, two identical sense resistors are required. The selection of appropriate sense resistors depends on following considerations: the maximum current to be sensed and the maximum power dissipation. To calculate the maximum power dissipation, assume full current scale (CS = 31) and full sense resistor voltage (vsense = 0, resulting in a sense resistor voltage of 320 mV). Select a part with an appropriate power rating. With vsense=1, the full scale voltage reduces to 180 mV. Choose a slightly lower value to compensate for trace resistance, e.g. 270 mΩ instead of 300 mΩ.