Placing FX2LP in Low Power Mode

Question: How can I place FX2LP in low power mode even when it is not connected to an active host?

 

Answer:

Inorder to unconditionally put the USB device into the low power state(irrespective of whether the cable is connected or not connected), you can simply write into the SUSPEND register and then set the PCON.0 bit as 1. 

 

Once in the low-power mode, there are three ways to wake up the EZ-USB:
1.USB activity on the EZ-USB’s DPLUS pin
2. Assertion of the WAKEUP pin
3. Assertion of the WU2 (“Wakeup 2”) pin
 
These three wakeup sources may be individually enabled by setting the DPEN, WUEN, and WU2EN bits in the Wakeup Control register.