NTI Functional and Architectural Specification

This paper presents the speci cation and prototype implementation of a printed circuit board termed Network Time Interface (NTI). Based on the M-Module industry standard, the NTI provides a turn-key solution for adding high-resolution synchronized clocks to fault-tolerant distributed systems built upon o -the-shelf hardware. It is built around our UTCSU-ASIC, which contains most of the hardware support required for external clock synchronization in distributed systems, like a rateand state-adjustable local clock, automatically maintained accuracy intervals, and provisions for connecting GPS receivers. Apart from interfacing the UTCSU to the rest of the system, the primary purpose of the NTI is to support accurate timestamping of clock synchronization data packets transmitted/received by network controllers with DMA-capabilities.