MICRO-MODEM RELIABILITY SOLUTION FOR NOC COMMUNICATIONS Arkadiy Morgenshtein, Evgeny Bolotin, Israel Cidon, Avinoam Kolodny, Ran Ginosar Technion – Israel Institute of Technology QNoC Research Group, Electrical Engineering Department Technion – Israel Institute of Technology Haifa, Israel

2 Micro-Modem – Reliability Solution for NoC Communications 2 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Outline Networks-on-Chip (NoC) Communication Environment Motivation Micro-Modem Architecture Components of Micro-Modem Discussion

3 Micro-Modem – Reliability Solution for NoC Communications 3 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Networks-on-Chip (NoC) NoC characteristics Packets-based data routing Modules connected by routers network Design modularity, various QoS levels Physical layer of NoC Submicron technologies Compact implementation Reliability challengesReliability challenges

4 Micro-Modem – Reliability Solution for NoC Communications 4 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Signal Integrity & Parameter Uncertainty Coupling capacitances QoS levels are physically adjacent Various activity factors Various frequency and packet sizes Device properties variations Nanoscale CMOS Threshold voltage variations Supply voltage variations interferences propagation delay Temperature variations Activity and power variations in NoC Wire delays Noise IR losses Leakage IR loss Aggressive Environment ! wire delay current drive noise leakage

5 Micro-Modem – Reliability Solution for NoC Communications 5 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Motivation Reliable data transportation Techniques for noise immunity Techniques for interference immunity Error identification and correction interferences propagation delay IR loss wire delay current drive noise leakage Uniform Communication Interface Scalable Reusable Adaptive Simple Compact Low-power Modem!

6 Micro-Modem – Reliability Solution for NoC Communications 6 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Modem in OSI Model of NoC Interconnect Application layer Presentation layer Session layer Transport layer Network layer Data link layer Physical layer

7 Micro-Modem – Reliability Solution for NoC Communications 7 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Micro-Modem Architecture

8 Micro-Modem – Reliability Solution for NoC Communications 8 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem INPUT BUFFER Can be embedded in the Router Stores the packet for further parallel processing Requires high-performance compact memory cells

9 Micro-Modem – Reliability Solution for NoC Communications 9 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem ERROR CORRECTION Implements error detection and correction Can be also used for restoration of bits lost - low-swing effects in low-area circuit designs - voltage drop in resistive wires - low signal integrity due to ISI, cross-talk and noise Has to be implemented using robust full-swing circuits

10 Micro-Modem – Reliability Solution for NoC Communications 10 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem SYNCHRONIZATION Clock recovery using 8x10 encoding Skew reduction between clock and data: - start/stop synch series for clock initiation - ack/req signals for GALS structures Sequence numbers for packets ordering and detection of lost packets

11 Micro-Modem – Reliability Solution for NoC Communications 11 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem INTERFERENCE REDUCTION Encoding / Processing for reduced crosstalk and ISI Interleaving for reduced potential differences in wires with opposite signals

12 Micro-Modem – Reliability Solution for NoC Communications 12 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem PARALLEL-TO-SERIAL CONVERTER Core device in serial data transportation Has to be ultra-high speed to compensate the loss of parallelism (scaling) Has to be compact and low-power Has to be designed for various lane widths scenarios, or as a generic unit

13 Micro-Modem – Reliability Solution for NoC Communications 13 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem MODULATION Low voltage differential signaling (LVDS) - Low-swing signaling - High noise and ISI immunity Multiplexing techniques

14 Micro-Modem – Reliability Solution for NoC Communications 14 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Components of Micro-Modem LINK INTERFACE Conditioning and buffering of the signal as it enters the wire Swing restoration Cascaded buffers for interconnect Fan-out drivers

15 Micro-Modem – Reliability Solution for NoC Communications 15 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Application of Micro-Modem can be function of noise and inter-system distance Possible µModem application types Application of Micro-Modem

16 Micro-Modem – Reliability Solution for NoC Communications 16 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Application of Micro-Modem Point-to-PointEnd-to-EndMid-Point High noise Parallel links High Latency High Power High Area Low noise Serial links Low Latency Low Power Low Area Medium.

17 Micro-Modem – Reliability Solution for NoC Communications 17 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Preliminary Designs 210x90um µ Modem Transmitter for Router 32-bit Micro-Modem in 0.25 µm technology

18 Micro-Modem – Reliability Solution for NoC Communications 18 Micro-Modem – Reliability Solution for NoC Communications ICECS 2004 Questions?