Micro-RDC Microelectronics Research Development Corporation A Programmable Scrubber for FPGAs ACKNOWLEDGMENT OF SUPPORT: This material is based upon work supported by the United States Air Force under Contract No. FA M Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the United States Air Force. G. Alonzo Vera

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Summary of reported solutions  Commonly implemented: Blind scrubbing  NASA/GSFC Radiation effects analysis group V4 scrubber (06/2007)‏  Some examples of read, detect, scrub  Sandia-Xilinx Virtex FPGA SEU experiment on the International Space Station. Cross scrubbing between V4 and V5.  LANL flight experiment for Virtex I and its derivations  BYU ICAP-based scrubber. Uses picoblaze  Radix4 configuration scrubber  Aeroflex Scrubber, an implementation of 989  XAPP 714: self scrubber, not longer supported  XAPP 779: V2 scrubber  XAPP 988: V4 scrubber  XAPP 989: lastest supported solution from Xilinx (V2/V4)‏

Commercially available solutions  Radix4 consulting  Works only for VirtexII family  Can be implemented as a peripheral or as stand alone  Mitigate SEUs and SEFIs  Uses 8-bit SelectMAP or ICAP Ref.: Radix4 Configuration Scrubber datasheet

Commercially available solutions  Aeroflex  Implements Xilinx's scrubber (XAPP989) on an Eclipse RadHard FPGA  For Virtex 4 family  Corrects and detect SEU  Uses 8-bit SelectMAP  Uses single CRC32 for the whole bitstream  Identifies SEFI's  Scrubs by pulling down PROG_B (whole device)‏  Doesn't support frame-based scrubbing Ref.: Aeroflex's XRTC 2009 presentation

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Agenda  Summary of reported solutions Design specification  Architecture  Extended Features  Status and testing plan

Design specification  Read/Write access to a memory-like configuration storage.  Error detection and correction using SECDEC or alternative.  Small footprint (originally thought as a “self-scrubber”).  Flexibility to implement different scrubbing rates and strategies, support different families and interfaces.  Deal with scrubber's own susceptibility to SEU (TMR?).  Others: Heartbeat signal, status and statistics on errors reporting capabilities, re-programming.

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Architecture  Femto: 8 bit, single cycle, micro-coded, “controller” “small footprint...” “error detection..” “flexibility...”“read/write access...”

FemtoCntrl: instructions

FemtoCntrl: Program example

PROM organization for Femto

Femto Flow

S-ASIC for rad-hard implementation A Low-Cost Solution for Low-Volume, Advanced Radiation-Hardened IC’s MPW Reticle → 10 Die w/Various Features

Femto's numbers  It currently occupies ~522 slices  XAPP989: ~ 200 to 1200 slices.  Others ??  Time to scrub ~ 0.2 sec MHz for 32Mbit PROM)‏  Instruccion memory: 256 instructions  CRC16 code book : 1024

Agenda  Requirements  Other reported solutions  Design specification Extended Features  Status and testing plan

Scrubber extended features  Selective scrubbing: flexible to implement different scrubbing rates and strategies

Scrubber extended features  Flexible deployment

Scrubber extended features  Support for other FPGA families or other devices (e.g. memories?)‏

Scrubber extended features  State reloading

Agenda  Summary of reported solutions  Design specification  Architecture  Extended Features  Status and testing plan

Agenda  Requirements  Other reported solutions  Architecture  Extended Features Status and testing plan

Testing Plan  Supporting components: Formal verification plan for software components (flow) and RTL (Q3-09)‏  Static testing: Fault injection / scrubbing automatic test (Q3-09)‏  Dynamic testing  Synthetic : Fault injection / detect / scrub / error monitoring (Q4-09)‏  Proton testing: radiate / detect / scrub / error monitoring (Q1-10)‏

Questions?