Systems and methods for synchronizing multiple digital audio controller
chips, wherein one of the chips is designated as a master and the other
chips are designated as slaves. A common line connects all of the chips
and is used to transmit synchronization signals from the master to the
slaves. Each of the chips listens for an appropriate signal and, when the
signal is detected, all of the chips simultaneously begin operation. In
one embodiment, the synchronization signal comprises a transition on the
shared line to an active state. The transition is repeated at fixed
intervals and maintained in the active state for a fixed period in order
to enable the chips to determine whether synchronization is being
maintained. The signal may be sampled and/or filtered to improve
reliability. The chips may be able to drive the shared line active to
indicate that synchronization has been lost.