The present invention provides a method for receiving an instruction for
varying the bus frequency from a current bus frequency to a new
frequency. The method may include storing a group of parameters
corresponding to a second frequency, disabling a link connected to the
host bus at a first frequency while the host bus is being operated with
parameters corresponding to the first frequency, updating the parameters
for operating the host bus with the group of parameters, and enabling the
link at the second bus frequency to operate the host bus with the group
of parameters.