Disconnecting the USB


We’re currently having a problem with the Cypress USB micro. We want to program via USB and then disconnect this interface (external power is provided), but when the connection is severed, the PLL stops clocking.

Is there any way to tell the USB micro to continue feeding a clock to the PLL, assuming that no further USB communication is required until a fresh power-up?

Many thanks,

The Manchester SCAMP team


Hi guys-

The Cypress chip will only stop outputting a clock when it enters suspend mode. This should not happen during a normal disconnect from power. It will happen, however, when the computer enters suspend or when it shuts down.