Ultra Low Power Embedded Systems

First sensor network CPU	Bringup board
ULSNAP chip as an Arduino shield

We are investigating the use of asynchronous circuits to attain ultra low power operation in the context of embedded systems.

For deeply embedded applications, the goal is to design a completely self-contained self-powered system. We collaborate with colleagues that have experitise in MEMS and micro-battery design so that the entire system is appropriately architected. For mobile applications, the goal is to develop systems that have a lifetime that is long enough so that users behave as if the mobile platform is always available.

We have designed a processor that uses an instruction set optimized for network protocol execution, and which can be connected to an RF data link to implement an efficient sensor node. The net result is a highly efficient microprocessor optimized for sensor network applications. This is the first published design of a microprocessor optimized for sensor networks.

We co-organized a workshop on sensors and sensor networks at Cornell (June 2003).

Collaborators

Sunil Bhave

François Guimbretière

Amit Lal

Participants

Mattia Vezzolli

Xiayuan Wen

Alums

Filipp Akopyan (Ph.D. 2011)

Virantha Ekanayake (Ph.D. 2005)

Clinton Kelly, IV (Ph.D. 2005)

Carlos Tadeo Ortega Otero (Ph.D. 2014)

Jonathan Tse (Ph.D. 2015)

Publications

Venkata Pavan Sumanth Sikhakollu, Shreesha Sreedhara, Rajit Manohar, Alan Mishchenko, and Jaijeet Roychowdhury. High Quality Circuit-based 3-SAT Mappings for Oscillator Ising Machines. International Conference on Unconventional Computation and Natural Computation, June 2024.

Prafull Purohit, Johannes Leugering, and Rajit Manohar. An Efficient Data Structure for Sparse Bit-Vectors with Applications in Neuromorphic Computing. IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), July 2023. (abstract, pdf)

Karthik Sriram, Raghavendra Pothukuchi, Michal Gerasimuk, Muhammed Ugur, Oliver Ye Rajit Manohar Anurag Khandelwal, and Abhishek Bhattacharjee. SCALO: An Accelerator-Rich Distributed System for Scalable Brain-Computer Interfacing . IEEE/ACM International Symposium on Computer Architecture (ISCA), July 2023. (abstract, pdf)   — Best paper award   — IEEE Micro Top Picks

Abhishek Bhattacharjee, Rajit Manohar, and Karthik Sriram,. RETROSPECTIVE: Hardware-software co-design for Brain-Computer Interfaces. ISCA@50 Retrospective, June 2023.    — ISCA-50 25-year retrospective

Ioannis Karageorgos, Karthik Sriran, Xiayuan Wen, Jan Vesely, Nick Lindsay, Michael Wu, Lenny Kazan, Raghavendra Pothukuchi, Rajit Manohar, and Abhishek Bhattacharjee. HALO: A Hardware-Software Co-Designed Processor for Brain-Computer Interfaces. IEEE Micro, Special issue from the HotChips 2022 conference, 2023.

Prafull Purohit and Rajit Manohar. Hierarchical Token Rings for Address-Event Encoding. IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), September 2021. (abstract, pdf)

Karthik Sriram, Ioannis Karageorgos, Jan Vesely, Nick Lindsay, Xiayuan Wen, Michael Wu, Marc Powell, David Borton, Rajit Manohar, Abhishek Bhattacharjee. Balancing Specialized Versus Flexible Computation in Brain-Computer Interfaces. IEEE Micro (special issue on Top Picks from Computer Architecture conferences), 2021. (pdf)

Ioannis Karageorgos, Karthik Sriram, Jan Vesely, Michael Wu, Marc Powell, David Borton, Rajit Manohar, and Abhishek Bhattacharjee. Hardware-software co-design for Brain-Computer Interfaces. Proceedings of the IEEE/ACM Symposium on Computer Architecture (ISCA), June 2020. (abstract, pdf)   — IEEE Micro Top Picks

Yu Chen, Xiaoyang Zhang, Yong Lian, Rajit Manohar, Yannis Tsividis. A Continuous-Time Digital IIR Filter with Signal-Derived Timing and Fully Agile Power Consumption. IEEE Journal of Solid-State Circuits, 53(2):418-430 (JSSC), February 2018. (abstract, pdf)

Yu Chen, Xiaoyang Zhang, Yong Lian, Rajit Manohar, and Yannis Tsividis. A Continuous-Time Digital IIR Filter with Signal-Derived Timing. 2017 Symposium on VLSI Circuits, June 2017. (abstract, pdf)

Yu Chen, Rajit Manohar, and Yannis Tsividis. Design of Tunable Delay Cells. Proceedings of the IEEE Custom Integrated Circuits Conference (CICC), May 2017. (abstract, pdf)

Carlos Tadeo Ortega Otero, Jonathan Tse, and Rajit Manohar. AES Hardware-Software Co-Design in WSN. IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), May 2015. (abstract, pdf)

Benjamin Tang, Sunil Bhave, and Rajit Manohar. Low Power Asynchronous VLSI with NEM Relays. Proceedings of the 20th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), May 2014. (abstract, pdf)   — Best paper nominee

Jaeyeon Kihm, François Guimbretière, Julia Karl, Rajit Manohar. Using Asymmetric Cores to Reduce Power Consumption for Interactive Devices with Bi-Stable Displays. Proceedings of the ACM CHI Conference on Human Factors in Computing Systems (CHI), April 2014. (abstract, pdf)

Carlos Tadeo Ortega Otero, Jonathan Tse, Robert Karmazin, Benjamin Hill, Rajit Manohar. ULSNAP: An Ultra-low Power Event-Driven Microcontroller for Sensor Network Nodes. Proceedings of the IEEE International Symposium on Quality Electronic Design, March 2014. (abstract, pdf)

François Guimbretière, Shenwei Liu, Han Wang, Rajit Manohar. An Asymmetric Dual-Processor Architecture for Low Power Information Appliances. ACM Transactions on Embedded Computing Systems, 13(4), February 2014. (abstract, pdf)

Jonathan Tse, Benjamin Hill, and Rajit Manohar. A Bit of Analysis on Self-Timed Single-Bit On-Chip Links. Proceedings of the 19th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), May 2013. (abstract, pdf)

Benjamin Tang, Stephen Longfield, Rajit Manohar, and Sunil Bhave. Low Power ASIC GPS Tracking Loops: Quantifying the Trade-Offs Between Area, Power and Accuracy. Proc. ION GNSS Technical Meeting, September 2012.    — Best presentation award

Benjamin Tang, Stephen Longfield, Sunil Bhave, and Rajit Manohar. A Low Power Asynchronous GPS Baseband Processor. Proceedings of the 18th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), May 2012. (abstract, pdf)

Carlos Tadeo Ortega Otero, Jonathan Tse, and Rajit Manohar. Static Power Reduction Techniques for Asynchronous Circuits. Proceedings of the 16th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), May 2010. (abstract, pdf)

Filipp Akopyan, Rajit Manohar, and A. Apsel. A level-crossing Flash Asynchronous Analog-to-Digital Converter. Proceedings of the 12th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), March 2006. (abstract, pdf)   — Best paper award

Yao-Win Hong, Birsen Sirkeci-Mergen, Anna Scaglione, and Rajit Manohar. Dense Sensor Networks are also Energy-efficient: when `more' is `less'. Proceedings of MILCOM 2005, October 2005. (abstract, pdf)   — IEEE Fred Ellersick Award for the best unclassified paper at MILCOM

Virantha Ekanayake, Clinton Kelly IV, and Rajit Manohar. An Ultra-low-power Processor for Sensor Networks. Proceedings of the 11th International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS), October 2004. (abstract, pdf, ps)

Clinton Kelly IV, Virantha Ekanayake, and Rajit Manohar. SNAP: A Sensor Network Asynchronous Processor. Proceedings of the 9th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC), pp. 24--33, Vancouver, BC, May 2003. (abstract, pdf, ps)

Rajit Manohar and Anna Scaglione. Power Optimal Routing in Wireless Networks. IEEE International Conference on Communications, pp. 2979--2984, Anchorage, AK, May 2003. (abstract, pdf)