arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.03070cs.NE
收藏

基于前向表的突触前事件触发的发放时间依赖可塑性

Forward Table-Based Presynaptic Event-Triggered Spike-Timing-Dependent Plasticity

Bruno U. Pedroni, Sadique Sheik, Siddharth Joshi, Georgios Detorakis, Somnath Paul, Charles Augustine, Emre Neftci, Gert Cauwenberghs

摘要:

尖峰时间依赖可塑性(STDP)招致因果和非因果突触权重更新,为负和正的时间差突触前和突触后尖峰事件。为了在神经形态硬件中实现这样的更新,当前的实现要么需要对突触连接表的前向和反向查找访问,要么依赖于存储器密集型架构,例如交叉开关阵列。我们提出了一种新的方法,用于实现因果和因果权重更新,只使用前向查找访问的突触连接表,允许内存高效的实现。在FPGA中的简化实现中,针对每个神经元使用单个定时器变量,对于大于10 ms的神经元不应期,非常接近精确的STDP累积权重更新,并且对于大于STDP时间窗口的不应期,简化为精确的STDP。与传统的crossbar实现相比,基于前向表的实现导致稀疏连接的网络支持具有完全可重构的突触连接性和可塑性的可扩展神经形态系统的大量存储器节省。

英文摘要:

Spike-timing-dependent plasticity (STDP) incurs both causal and acausal synaptic weight updates, for negative and positive time differences between pre-synaptic and post-synaptic spike events. For realizing such updates in neuromorphic hardware, current implementations either require forward and reverse lookup access to the synaptic connectivity table, or rely on memory-intensive architectures such as crossbar arrays. We present a novel method for realizing both causal and acausal weight updates using only forward lookup access of the synaptic connectivity table, permitting memory-efficient implementation. A simplified implementation in FPGA, using a single timer variable for each neuron, closely approximates exact STDP cumulative weight updates for neuron refractory periods greater than 10 ms, and reduces to exact STDP for refractory periods greater than the STDP time window. Compared to conventional crossbar implementation, the forward table-based implementation leads to substantial memory savings for sparsely connected networks supporting scalable neuromorphic systems with fully reconfigurable synaptic connectivity and plasticity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑