QoS-supported On-chip Communication for Multi-processors

Abstract

We present a Quality of Service (QoS)-supported on-chip communication that increases the shared communication resources for multi-processor systems on chip. Time-critical embedded systems require tight guaranteed services in terms of throughput, latency etc. in order to comply to hard real-time constraints. Typically, guaranteed-service schemes require dedicated/reserved resources (i.e. links) for communication and thus suffer from low resource utilization. So improving the bandwidth utilization by using the unused bandwidth among the other competing transactions in a fair fashion is an important issue. To the best of our knowledge, we are presenting the first approach for on-chip communication that provides a high resource utilization under a transaction-specific, flexible communication scheme. It provides tight timerelated guarantees through our bounded arbitration scheme considering the lower and the upper bounds for each type of transactions. We demonstrate its advantages by means of a complete MPEG4 video decoder case study analysis and achieve under certain constraints a bandwidth utilization of up to 100% and 97% on average with a guaranteed 100% bandwidth. Thus, we provide an on-chip communication scheme that provides high bandwidth utilization while providing tight guarantee.

Combining SDM-Based Circuit Switching with Packet Switching in a Router for On-Chip Networks

“…Reserved time slots are used to carry streaming traffic, while unreserved time slots are used to carry best-effort traffic [1]. However, providing QoS and sharing resources between streaming and besteffort traffic are hard and often lead to a complex design with 2 International Journal of Reconfigurable Computing huge hardware and power consumption overhead [2]. In packet-switched network, streaming and best-effort traffics are handled by either assigning priorities to each type of traffic, with streaming traffic having the highest priority, [3] or by reserving buffers or virtual channels "VCs" for carrying the streaming traffic, while the unreserved buffers are used to carry the best-effort traffic [4].…”

“…SDM-TDM path between source (2,1) and destination(2,3). Failed path establishment in SDM-TDM-based NoC.…”

A hybrid NoC combining SDM-TDM based circuit-switching with packet-switching for real-time applications

“…To handle streaming traffic in a packet-switched NoC, additional protocols must be implemented. These protocols consist in either assigning priorities to different types of traffic [2] or reserving buffers (Virtual channels) for streaming traffic [1]. However, these additional protocols come with a huge area and power consumption overhead.…”