crossbar dimensions, routing topologies, and neuron primitives-deep within their intermediate representations
and optimization passes.
[5]
This tight coupling results in brittle toolchains that require significant redesign to
support emerging neuromorphic substrates.
2.3 Dataflow and cluster-based mapping frameworks
To improve portability and analytical tractability, several frameworks adopt dataflow-driven or cluster-based
compilation strategies. DFSynthesizer introduces a pipeline that partitions SNN workloads into hardware-
constrained clusters, models them as synchronous dataflow graphs, and schedules execution under bandwidth
and latency constraints.
[8]
Complementary approaches such as SpiNeMap emphasize synaptic clustering based
on functional proximity to reduce routing overhead and inter-core communication.
[9]
Although these methods
improve mapping quality and enable performance analysis, they often rely on simplified abstractions such as
homogeneous tiles or crossbars. As a result, they struggle to capture the diversity of modern neuromorphic
fabrics, including irregular interconnects and mixed analog–digital architectures.
[4,13]
2.4 Spatial/temporal placement & optimization heuristics
Placement-oriented tools such as NeuMap apply fast heuristic and metaheuristic strategies to reduce network-
on-chip latency and energy consumption by colocating neurons with high communication affinity.
[10]
These
techniques are often combined with communication-aware partitioning to reduce spike traffic in large-scale
deployments.
[13]
While heuristic placement scales well, it typically optimizes a narrow objective, such as
communication locality. Important aspects—including timing jitter, asynchronous execution behavior, and
online plasticity—are often excluded, limiting robustness in heterogeneous and adaptive neuromorphic
systems.
[14]
2.5 Modular architectures and reusable design patterns
Several studies propose modular and parameterized spike-based building blocks that encapsulate common
computations such as feature extraction, pooling, and normalization.
[11]
These abstractions simplify SNN
composition and improve reasoning about verification and resource usage. Despite these advantages, modular
patterns are not yet first-class citizens in neuromorphic compilers. Without a shared abstraction layer or
pattern-aware intermediate representation, such constructs remain library-level conveniences rather than
integrated compilation primitives.
[15]
2.6 FPGA implementations and prototyping platforms
FPGA-based SNN implementations provide flexible platforms for algorithm–hardware co-design and support
custom spike encodings and online learning mechanisms.
[12,16]
These platforms enable rapid experimentation
prior to committing designs to silicon. However, FPGA architectures differ significantly from neuromorphic
chips in communication models and timing semantics. Consequently, mapping strategies effective on FPGAs do
not directly translate to specialized neuromorphic fabrics, and many FPGA-based efforts emphasize functional
validation rather than full compilation automation.
[16]
2.7 Surveys, trends, and device-level progress (materials to chips)
Comprehensive surveys and benchmark studies document strong progress in neuromorphic computing,
spanning large-scale digital processors, mixed-signal systems, and emerging synaptic devices such as
ferroelectric FETs.
[1,6,17]
These works consistently emphasize the need for cross-layer toolchains that jointly
account for device characteristics, learning rules, and system-level constraints. As the hardware landscape
continues to diversify, existing toolchains—often built around rigid architectural abstractions—struggle to
remain broadly applicable, widening the gap between device innovation and software support.
[2,3]
2.8 Comparative analysis & limitations across approaches
Generality vs. performance trade-off: Platform-specific compilers (e.g., NxTF) achieve strong performance on a
single chip but do not generalize; dataflow-based and clustering frameworks are more portable conceptually
but still assume specific hardware abstractions (tiles, crossbars).
[7]
Support for adaptation & online learning:
Few toolchains include built-in, first-class support for plasticity, continuous adaptation, or online learning; most
focus on static mapping of inference workloads.
[14]
Automation depth: Several systems require manual tuning
(e.g., cluster sizes, mapping parameters, scheduling tweaks). End-to-end automation that jointly optimizes
accuracy, latency, energy, and hardware constraints remains limited.
[9, 10]
Hardware heterogeneity: The
expanding variety of synaptic device technologies and interconnect topologies makes a one-size-fits-all
compiler difficult; current tools either abstract away critical device details or hard-wire assumptions that break
portability.
[11,15]
2.9 Identified research gap motivating the UNAL framework