Fault Tolerance - Universidad de Sevilla - Hardware Debugging System


FTUNSHADES is a hardware-accelerated fault injection platform for early assessment of the robustness of a circuit to SEE.

The system emulates a circuit running on an FPGA (Xilinx V5). Playing with the configuration bits, the runtime value of any selected register is flipped in a certain clock cycle, and its effects assessed.

The goal is to inspect a design, determine where protections should be inserted in the circuit architecture, and what the limits of those protections are.

What can it do for me?

Campaign mode

FTUNSHADES campaigns are tailor made for injecting massive amounts of faults and automatically retrieve as much information as possible.

The targeted registers may be specified manually from every point of the hierarchy. Many options, modes and SEE models may be configured through the user friendly GUI.

Debug mode

Debugging allows the interruption of a campaign at arbitrary points to extract even more information from the system. Once interrupted, the system may be manually analyzed step by step.

FPGA mode

A campaign in which the FPGA itself is the target device. Configuration bits are selected and flipped as would happen to registers during a campaign.

Microprocessor mode

Fault detection is usually performed cycle by cycle. This condition is too much restrictive for systems like an embedded processor, where protections are inserted via software redundancies. An original technique called "smart table" has been implemented.

Diagnose faults

For fault diagnosis, a technique based on hash codes has been developed to analyse and compare the signatures of faults in a fault injection campaign with the real circuit in the accelerator beam.

Selective hardening

After fault injection detects the most sensitive parts of a design, it is advisable to harden those. For this, we provide a VHDL package for fine-grain circuit hardening, the triple-logic package.

How do I make it work?

FTUNSHADES uses the standard Xilinx design flow. The user only needs to provide a list of I/O pins. The workflow is simple and the interface itself guides you step by step.

The only limits are:

FTUNSHADES devices are able to extract the following information:

Where can I use it?

FTUNSHADES is available on the cloud, free of charge, to public research institutions.

A proposal of research activity must be sent to the development team specifying the subject, mode of use, and time window needed. The development team will decide the access mode and credentials will be sent to the research activity responsible.

Note that few nodes are available and we can receive many requests.

As counterparty, the University of Sevilla will send an agreement with the terms of use and responsibility to signed by a legal authority of the research institution.

All publications produced by that activity must mention the FTUNSHADES project, the University of Sevilla and European Space Agency in the Acknowledgements section.


FTUNSHADES development team (in alphabetical order)

Collaborators and historical actors



Hipólito Guzmán-Miranda
Fernando Muñoz Chavero
Miguel A. Aguirre
Escuela Superior de Ingenieros, Departamento de Ingeniería Electrónica. Camino de los descubrimientos s/n 41092 Sevilla (SPAIN)