self-repairing electronic logic units based on convergent cellular … · 2015. 12. 20. · hillock...

TESConf 5-6 Nov 2012 TESConf 5-6 Nov 2012

Self-repairing electronic logic units based on convergent cellular automata

Richard McWilliam

TESConf 5-6 Nov 2012

The need for fault-tolerant electronic systems

Self-repair bring big benefits to MRO

• Better in-flight fault detection • Register self-repair events • Improve scheduled maintenance

Quantas flight 72

• Suffered in-flight upset (suspected SEE) • Failure of air data inertial reference unit • Flight control primary computer could not

handle data • 12 serious injuries, 95 minor injuries


Mission critical electronics

Single Event Upsets (SEU)

Especially prevalent in SRAM

Resulted in rad-hardened devices

Virtex-5QV

Cibola flight experiment (CFESat)

9x Virtex 1000 (6M bits) launched 2007

Low orbit, SEU rates varied from 0.13/hr (quiet

sun) to maximum of 4.2/hr

See e.g., M. Wirthlin, et al, 11th Annual IEEE Symp. On field-programmable custom computing machines, 2003, pp. 133-142

NASA Radiation Belt Storm Probes (RBSP) mission


Microsystems Packaging failure mechanisms

Wearout Mechanisms Overstress Mechanisms

Mechanical Electrical

Brittle fracture

Plastic

Deformation

Interfacial

delamination

EMI

ESD

Radiation

Gate oxide

Breakdown

Interconnect

Melting

Mechanical Chemical Electrical

Fatigue damage

Creep

Wear

Stress-driven

voiding

Interfacial

delamination

Hillock formation

Junction spiking

Electromigration

Corrosion

Diffusion

Dendritic growth

(Source: Fundamentals of Microsystems Packaging by Rao Tummala)

Root cause Failure analysis: Electronics


Self-recovery strategies

Fault-tolerant structures contain redundancy to permit one or more fault occurrence. E.g., EDC or Quadded logic. Self-repair requires reconfiguration after the fault event. Self-preservation takes pre-emptive actions to minimise effects of impending fault event (health monitoring, data analysis).

Self-recovery Self-recovery


Built-in self-test and repair:

BISTAR (Other related: BIST,BISD,BIRA,BISR)

Built-in logic, but not self-repairing.

Goal is BISTAR at system level:

E.g., A. Benso, et al, “An on-line BIST RAM architecture with self-repair capabilities,” IEEE Transactions on Reliability, vol. 51, no. 1, pp. 123 –128, Mar. 2002.


Towards BISTAR

Self-healing system

Built-in reconfiguration is hard to do in electronics


Towards self-repair

Sea of logic and

switching

BIS

R

BIS

D

Self-restoration

Goals

BISDAR within a ‘sea of logic’

Self-restoring (transient upsets)

Fault tolerant with redundancy (hard faults)

Does not require major in-circuit reprogramming


Cellular electronics approach

Composed of many identical ‘cells’

Each cell contains a copy of rules

Global output state depends on the rules and boundary conditions

O

O

I1

I2

I1 I2 O

0 1 0

2 5 -1

LUT Cellular Automata

A (t=0)

cell

boundary

CA (t=1)


Convergent Cellular Automata (CCA)

0)( DCAI final

2,2

1,2

2,1

1,1

C

C

C

C

C

0

0

0

0

10

010

001

0001

2,2

1,2

2,1

1,1

d

d

d

d

C

C

C

C

wn

n

w

C1,1 C1,2

C2,1 C2,2

Boundary=0

Boundary

=0

Define a transition function:

Apply convergence criteria to attain

A = transition matrix

D = constant DCC currentnext A

dwC tjitjitji ,1,,,11,, CnC

finalC


CCA Example

Solving above equation:

1 0

0 1

Goal 0 0

0 0

1 1

1 1

1 0

0 -1

1 0

0 1

3 7

-1 5

1 -2

-2 -5

1 0

0 5

1 0

0 1

0

0

0

0

1

0

0

1

10

010

001

0001

d

d

d

d

wn

n

w

Convergence: zero initial state

Convergence: random initial state

(i.e., d=1,n=-1,w=-1)

tjitjitji wC ,1,,,11,, CC-1

finalC

D. Jones, R. McWilliam, and A. Purvis, “Designing convergent cellular automata.” Biosystems, vol. 96, no. 1, pp. 80–85, 2008.


Stem cell algorithm: Self-organised behavior


Dynamic CCA


CCA as coordination layer


On-going work: test platform

Change boundary condition to (4,7)

Full adder logic element


On-going work: test platform


Future work

Subject complete CCA coordination logic to SEUs

Fault injection hardware integrated with MSTS (thermal, electrical, radiation)

ISIS facility Rutherford and Appleton Laboratory (UK), Chipir high energy neutron source (800 MeV)

MSTS Hardware

Routing

logic

Control

Introduce fault tolerant architecture to functional logic layer.


Thank you

Publications

Jones, David, McWilliam, Richard & Purvis, Alan 2008. Designing convergent cellular automata. Biosystems 96(1): 80-85.

Jones, David, McWilliam, Richard. & Purvis, Alan. 2010. Design of a self-assembling, repairing and reconfiguring Arithmetic Logic Unit. In New Advanced Technologies. Aleksandar Lazinica Vienna, Austria: Intech Education and Publishing. 161-176. (http://sciyo.com/books/show/title/new-advanced-technologies)

Jones, D.H., McWilliam, R. & Purvis, A. 2011. Convergence and feedback: a framework for cellular automata design. Journal of Cellular Automata 6(4-5): 399-416
http://sciyo.com/books/show/title/new-advanced-technologieshttp://sciyo.com/books/show/title/new-advanced-technologieshttp://sciyo.com/books/show/title/new-advanced-technologieshttp://sciyo.com/books/show/title/new-advanced-technologieshttp://sciyo.com/books/show/title/new-advanced-technologies

self-repairing electronic logic units based on convergent cellular … · 2015. 12. 20. · hillock...

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