Time error accumulation in a hierarchical time and clock distribution network with deterministic optical links

Abstract

Accurate clock and time distribution is a key requirement for self-triggered streaming data acquisition in the CBM experiment. This distribution is handled by the Timing and Fast Control (TFC) system by clock forwarding and broadcasting the common time over latency-deterministic optical links in a hierarchical FPGA network. The point-to-point optical connections are served by the latency-optimized GBT-FPGA core, which has been developed at CERN. In the presented work, the performance of GBT-FPGA links for time and clock distribution in a scaled TFC system with multiple hops and endpoints has been investigated.