Abstract

This paper presents verification and implementation methods that have been developed for the design of the BrainScaleS-2 65 nm ASICs. The 2nd generation BrainScaleS chips are mixed-signal devices with tight coupling between full-custom analog neuromorphic circuits and two general purpose microprocessors (PPU) with SIMD extension for on-chip learning and plasticity. Simulation methods for automated analysis and pre-tapeout calibration of the highly parameterizable analog neuron and synapse circuits and for hardware-software co-development of the digital logic and software stack are presented. Accelerated operation of neuromorphic circuits and highly-parallel digital data buses between the full-custom neuromorphic part and the PPU require custom methodologies to close the digital signal timing at the interfaces. Novel extensions to the standard digital physical implementation design flow are highlighted. We present early results from the first full-size BrainScaleS-2 ASIC containing 512 neurons and 130 K synapses, demonstrating the successful application of these methods. An application example illustrates the full functionality of the BrainScaleS-2 hybrid plasticity architecture.

Highlights

  • The design of neuromorphic hardware follows the goal to model parts, or at least functional aspects, of the biological nervous system

  • For TrueNorth and Loihi these strategies have been outlined in [5] and [15], respectively. Such information is otherwise only sparsely available. To improve on this situation, this paper describes selected aspects of the implementation and verification strategies employed in the design of different versions of the BrainScaleS-2 neuromorphic chips

  • The mixed-signal BrainScaleS-2 ASIC contains very-large-scale integration (VLSI) analog neuromorphic circuits, digital control and communication infrastructure, and one or more general-purpose microprocessors mainly intended to be used as plasticity processing units (PPUs)

Read more

Summary

Introduction

The design of neuromorphic hardware follows the goal to model parts, or at least functional aspects, of the biological nervous system. TrueNorth [33] is a neuromorphic chip that integrates 4096 neurosynaptic cores to simulate 1 M neurons and 256 M synaptic connections at biological realtime It is fully digital and the cores are operated asynchronously. While the aforementioned systems are implemented using digital logic, analog neuromorphic designs make use of dedicated analog circuits as computational elements, which is beneficial in terms of energy and cost efficiency and their continuous-time operation reproduces the collective dynamics of neural networks more faithfully. Such information is otherwise only sparsely available To improve on this situation, this paper describes selected aspects of the implementation and verification strategies employed in the design of different versions of the BrainScaleS-2 neuromorphic chips.

BrainScaleS Architecture
Analog Neural Network Core
Hybrid Plasticity
Digital Control
Verification Methods
Full-Custom Verification
Interfacing Analog Simulations from Python
Monte Carlo Calibration
Physical Implementation
Timing Analysis at Mixed-Signal Interfaces
Timing Characterization of Anncore
Anncore Abstract View
Mixed-Signal Event Input
Partition Interface Timing
Partition and Top-Level Implementation
Applications
Discussion
10. Cadence Design Systems
38. PowerISA
Findings
47. Taiwan Semiconductor Manufacturing Company

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.