An ASIC supporting external clock synchronization for distributed real-time systems

Less pessimistic worst-case delay analysis for packet-switched networks

“…The nodes are assumed to be clock synchronized but in practice there will be a clock drift in between synchronizations. However, typical clock drift in a clock synchronized wide area real-time system range from hundred nanoseconds up to microseconds [8], so in this experiment it is assumed that the clock drift is negligible. It is assumed that all cables in the system are short, less than a meter, and of approximately same length which results in a cable delay in the nanosecond range, which is negligible.…”

Building fault-tolerant hardware clocks from COTS components

“…The approach closest to the one described in this paper is the SynchUTC project of Schmid and Schossmaier [9,10]. Their approach uses an ASIC that implements a clock that is synchronized with UTC via a GPS receiver.…”

“…Assume we want to determine the value of H C at real-time v and we know its value H C u for some earlier time u. Also assume that u is the time of the most recent update of avg before v. We define H C v by H C v : = H N v , H N u 1 + avg + H C u Eq : 7 = NHv , Hu 1 + avg + H C u: (10) We assume that there exists a time u 0 at which avg is measured for the first time.…”