................................................................................................................................................................. 3 1 Authors and Participants............................................................................................................................ 4 2 Actions Related to IC&D ............................................................................................................................ 5 2.1 Public Deliverables ................................................................................................................................. 5 2.2 Publications and Awards........................................................................................................................ 5 3 Description of ASIC .................................................................................................................................... 8 4 Implementation.......................................................................................................................................... 15 4.1 Specifications......................................................................................................................................... 15 4.2 Design trade-offs ................................................................................................................................... 17 4.3 Block Diagram ...................................................................................................................................... 18 4.4 Algorithms used .................................................................................................................................... 19 4.4.1 Signature Analyzing Mechanism ....................................................................................................... 19 4.4.2 Priority Interrupt Controller (PIC) ..................................................................................................... 19 4.4.3 Watchdog Timer ................................................................................................................................ 20 4.4.4 Routine Timer .................................................................................................................................... 20 4.4.5 Motor Controller ................................................................................................................................ 21 4.5 Timing Analysis .................................................................................................................................... 21 4.6 Verification & Simulation .................................................................................................................... 22 4.7 Post-Layout ........................................................................................................................................... 23 4.8 Testability .............................................................................................................................................. 24 5 Datasheet* .................................................................................................................................................. 25 6 Summary .................................................................................................................................................... 26 7 References .................................................................................................................................................. 27 CoSafe: Design Story March 2002 MICREL Medical Devices S.A. Ithakis 4 Pallini GR15351 Athens Greece University of Patras VLSI Design Lab. Dpt. of Electrical & Computer Eng. Rio, GR-26500 Patras, Greece 3 ABSTRACT A microcontroller to support portable medical applications has been developed by our team and is presented in this report. Its main characteristics are its low power dissipation that enables portability of the final product and safe operation in order to be used in medical applications. A medicine infusion device has served as the application vehicle to evaluate the correctness of the development methodology. The European Union through the ESD Cluster funded the development of this system, in the bounds of the ESPRIT projects. Micrel medical devices Ltd that also funded in part the CoSafe project provided the specifications of the final system. A prototype of the ASIP was fabricated in the manufacturing center of FhG-IIS, as part of the services that Europractice offers to academic institutions. Special concern had been given to the design of self-checking and self-testing circuits to enable concurrent error detection. These circuits were used to provide the ability of error detection when an error occurs. This technique allows enhancement of the Self-Test property while safety is maintained in high levels without the use of multi-channeled structures. Additionally, special structures to allow safe application code execution have been developed. The prototype ASIC also integrates a sophisticated motor controller in order to drive more efficiently the pump of the device. This controller has also been developed using the methodology to design low-power soft-error detecting systems. The system was been enhanced further to classify errors in non-accumulative and accumulative. Thus, tolerance of the non-accumulative errors was achieved through the application of a rollback algorithm. According to this algorithm, the last executed instruction is executed again when a nonaccumulative error is detected. Due to the structure of the system that enables concurrent error detection, the depth of backup state is minimized as well as also the code execution latency. The prototype met the constraints of the application both in terms of safety and low power dissipation. Finally, area overhead was kept low. A system board has been fabricated to exhibit the potentiality of the ASIC to European Union and Micrel Ltd. CoSafe: Design Story March 2002 MICREL Medical Devices S.A. Ithakis 4 Pallini GR15351 Athens Greece University of Patras VLSI Design Lab. Dpt. of Electrical & Computer Eng. Rio, GR-26500 Patras, Greece 4 1 AUTHORS AND PARTICIPANTS Costas E. Goutis University of Patras goutis@ee.upatras.gr Spiros Nikolaidis Aristotle University of Thessaloniki snikolaid@physics.auth.gr Alexandros Tsoukalis Micrelmed Medical Devices S.A. info@micrelmed.com Kyriakos Papadomanolakis University of Patras papk@ee.upatras.gr Athanasios Kakarountas University of Patras kakaruda@ee.upatras.gr Vassilis Spiliotopoulos University of Patras bspili@ee.upatras.gr Eythimakis Karaolis Aristotle University of Thessaloniki karaolis@physics.auth.gr Vassilis Kokkinos University of Patras kokkinos@ee.upatras.gr Spiros Theoharis now with Alma Technologies theohar@ee.upatras.gr CoSafe: Design Story March 2002 MICREL Medical Devices S.A. Ithakis 4 Pallini GR15351 Athens Greece University of Patras VLSI Design Lab. Dpt. of Electrical & Computer Eng. Rio, GR-26500 Patras, Greece 5 2 ACTIONS RELATED TO IC&D 2.1 PUBLIC DELIVERABLES D1.2R1 Specifications of the Safety mechanisms of the ASIP D2.1R1 Low Power design methodology for Safety-Critical applications D3.2R1 Instruction Set of the ASIP D1IC&D Specifications of the Safety mechanisms of the ASIP D2IC&D Low Power design methodology for Safety-Critical applications D3IC&D Low-Power co-design flow supported by the established environment D4IC&D Software developed and integrated in the co-design environment D5IC&D Instruction Set and Architecture of the ASIP 2.2 PUBLICATIONS AND AWARDS Awards: [A1] Conceptual Design contest of DATE 2002, sponsored by Europractice, Paris, France, March, 2002 for the work presented by A.P. Kakarountas, K.S. Papadomanolakis, V. Spiliotopoulos, S. Theoharis, E. Karaolis, V. Kokkinos, with title "Designing a low-power soft-error fault-tolerant medicine infusion device". [A2] Higher Education Program Student Design Contest 2002, SOC and PCB Category prizes, sponsored by Mentor Graphics & Sun Microsystems for the work "COSAFE: A low-power medicine infusion pump" K.S. Papadomanolakis, A.P. Kakarountas, K.S. Papadomanolakis, V. Spiliotopoulos, E. Karaolis, V. Kokkinos, E. Karaolis.