According to one embodiment, an apparatus includes a first processing unit operating according to a first clock, a second processing unit operating according to a second clock running separately from the first clock, and a synchronization controller coupled to the first communication unit and the second communication unit. The synchronization controller is configured to (i) cause the first communication unit to generate a first indication of time at which the first processing unit transmits a signal to the second processing unit, according to the first clock, (ii) cause the second processing unit to generate a second indication of time at which the second processing unit receives the signal, according to the second clock, and (iii) determine an offset between the first clock and the second clock based on the first indication of time and the second indication of time.