micro-modem reliability solution for noc communications arkadiy morgenshtein, evgeny bolotin, israel...

MICRO-MODEMMICRO-MODEM

RELIABILITY SOLUTION FOR NOC RELIABILITY SOLUTION FOR NOC

COMMUNICATIONSCOMMUNICATIONS

Arkadiy Morgenshtein, Evgeny Bolotin, Israel Cidon, Avinoam Kolodny, Ran Arkadiy Morgenshtein, Evgeny Bolotin, Israel Cidon, Avinoam Kolodny, Ran GinosarGinosar

Technion – Israel Institute of Technology

QNoC

Research

Group

QNoC Research Group, Electrical Engineering DepartmentTechnion – Israel Institute of Technology

Haifa, Israel

22 Micro-Modem – Reliability Solution for NoC CommunicationsMicro-Modem – Reliability Solution for NoC Communications ICECS 2004

OutlineOutline

•Networks-on-Chip (NoC)

•Communication Environment

•Motivation

•Micro-Modem Architecture

•Components of Micro-Modem

•Discussion


Networks-on-Chip (NoC)Networks-on-Chip (NoC)

Router

Module

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


Router

Module

Signal Integrity & Parameter Signal Integrity & Parameter UncertaintyUncertainty

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

interferences

prop

agat

ion

dela

y

prop

agat

ion

dela

y

Temperature variations

• Activity and power variations in NoC• Wire delays• Noise• IR losses• Leakage

IR lossIR loss

Aggressive Aggressive EnvironmentEnvironment

!!wire

delay

wire delay

current drive

current drive

noisenoise

leakageleakage


Router

Module

MotivationMotivation

Reliable data transportation

• Techniques for noise immunity• Techniques for interference immunity • Error identification and correction

interferences

interferences

prop

agat

ion

dela

y

prop

agat

ion

dela

y

IR lossIR loss

wire delay

wire delay

current drive

current drive

noisenoise

leakageleakage

Uniform Communication Interface

• Scalable• Reusable• Adaptive

• Simple• Compact• Low-power

Modem!Modem!


Modem in OSI Model of NoCModem in OSI Model of NoC

Interconnect

Application layer

Presentation layer

Session layer

Transport layer

Network layer

Data link layer

Physical layer

Router

Mo

dem

Modem

Mo

dem

Modem


Micro-Modem ArchitectureMicro-Modem Architecture

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction

Parallel-to-Serial Converter

Router

Modulation

Link Interface

Interconnect

Router

µModem

µM

odem

µModemµM

odem

Router

µModem

µM

odem

µModem

µMod

em


Components of Micro-Components of Micro-ModemModem

INPUT BUFFER

• Can be embedded in the Router

• Stores the packet for further parallel processing

• Requires high-performance compact memory cells

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



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

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



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

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



INTERFERENCE REDUCTION

• Encoding / Processing for reduced crosstalk and ISI

• Interleaving for reduced potential differences in wires with opposite signals

A

A

A

Aint

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



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

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



MODULATION

• Low voltage differential signaling (LVDS) - Low-swing signaling - High noise and ISI immunity

• Multiplexing techniques

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect



LINK INTERFACE

• Conditioning and buffering of the signal as it enters the wire

• Swing restoration

• Cascaded buffers for interconnect

• Fan-out drivers

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect


Application of Micro-Modem can be function of noise and inter-system distance

Point-to-PointMid-Points

Mid-PointsEnd-to-End

TransportRange

NoiseLevel

high

longshort

low

Possible µModem application types

Application of Micro-ModemApplication of Micro-Modem


Application of Micro-ModemApplication of Micro-ModemPoint-to-Point End-to-EndMid-Point

High noise

Parallel links

High Latency

High Power

High Area

Low noise

Serial links

Low Latency

Low Power

Low Area

Medium

.

.

.

.


Preliminary DesignsPreliminary Designs

210x90um µModem Transmitter for Router

32-bit Micro-Modem in 0.25 µm technology


Questions?Questions?

InputBuffer

Error Correction

Synchronization

n

m

ISI reduction


Router

Modulation

Link Interface

Interconnect

Router

µModem

µM

odem

µModemµM

odem

Router

µModem

µM

odem

µModem

µMod

em

micro-modem reliability solution for noc communications arkadiy morgenshtein, evgeny bolotin, israel...

Documents

noc communications icecs

micromodem architecture

power variations

noise immunity techniques

israel cidon

lowswing effects

error detection

outline networks