Channel trees: reducing latency by sharing time slots in time-multiplexed networks on chip

Networks on Chip (NoC) have emerged as the design paradigm for scalable System on Chip communication infrastructure. A growing number of applications, often with firm (FRT) or soft real-time (SRT) requirements, are integrated on the same chip. To provide time-related guarantees, NoC resources are reserved, e.g. by non-work-conserving timedivision multiplexing (TDM). Traditionally, reservations are made on a per-communication-channel basis, thus providing FRT guarantees to individual channels. For SRT applications, this strategy is overly restrictive, as slack bandwidth is not used to improve performance. In this paper we introduce the concept of channel trees, where time slots are reserved for sets of communication channels. By employing work-conserving arbitration within a tree, we exploit the inherent single-threaded behaviour of the resource at the root of the tree, resulting in a drastic reduction in both average-case latency and TDM-table size. We show how channel trees enable u...

• Type: Conference
• Year: 2007
• Where: CODES
• Authors: Andreas Hansson, Martijn Coenen, Kees Goossens
• Keywords: Channel Trees, Chip Communication Infrastructure, CODES 2007, Hardware-Software Codesign, Inherent Single-threaded Behaviour