A hub based computer system having a central hub that communicates with a
plurality of satellite devices over respective link buses. Each link bus
is substantially the same and adheres to a predefined link bus protocol.
The link bus protocol establishes a method in which data receiving
circuitry of a target device can be put into a known state during a final
stage of a source strobe event such as e.g., a data transfer. Once in the
known state, the source strobes are stopped on the link bus. The target
device uses internal logic clocked by a system clock rather than the
source strobe to continuously sample the state of the receiving circuitry
to see if the state has deviated from the known state. A change detect
circuit determines if the receiving circuitry has deviated from the known
state and if so, detects a new source strobe event. The change detect
circuit detects the new event in the less stringent clock domain, which
allows greater control of the skew and asymmetry of the source strobe.
This allows the system to achieve substantially higher data transfer rates
than conventional source strobe systems.