Port Multipliers and Selectors 419
enable/disable spread spectrum clocking if it is settable. There is no means within the Serial ATA pro-
tocol provided to enable/disable spread spectrum clocking, if it is statically configurable.
If spread spectrum clocking is used, the spreading domain between the host and the Port Selector
is not required to be the same as the spreading domain between the device and the Port Selector. The
signals passing through a Port Selector may be re-spread.
9.15 Power-up and Resets
9.15.1 Power-up
Upon power-up, the Port Selector will reset all internal state, including the active host port. This will
cause no active host port to be selected when protocol-based port selection is used.
Presence Detection of Port Selec