I have a PNP resistor. The supply voltage is 3V and the current draw out the other end is 160mA. I am trying to determine the resistor value between the digital pin and the base. The micro controller is running at 3V. Does anyone know the exact resistance and watts that the resistor should be able to dissipate? Hopefully I have provided enough information, but please let me know if I have not.

If you could explain how you get the answer that would be greatly appreciated so that I will know how to in the future. Thanks in advance for your help.