On Multiple AER Handshaking Channels Over High-Speed Bit-Serial Bidirectional LVDS Links With Flow-Control and Clock-Correction on Commercial FPGAs for Scalable Neuromorphic Systems

Amirreza Yousefzadeh, Miroslaw Jablonski, Taras Iakymchuk, Alejandro Linares-Barranco, Alfredo Rosado, Luis A. Plana, Steve Temple, Teresa Serrano-Gotarredona, Steve B. Furber, Bernabe Linares-Barranco
2017 IEEE Transactions on Biomedical Circuits and Systems  
Address event representation (AER) is a widely employed asynchronous technique for interchanging "neural spikes" between different hardware elements in neuromorphic systems. Each neuron or cell in a chip or a system is assigned an address (or ID), which is typically communicated through a highspeed digital bus, thus time-multiplexing a high number of neural connections. Conventional AER links use parallel physical wires Manuscript together with a pair of handshaking signals (request and
more » ... dge). In this paper, we present a fully serial implementation using bidirectional SATA connectors with a pair of low-voltage differential signaling (LVDS) wires for each direction. The proposed implementation can multiplex a number of conventional parallel AER links for each physical LVDS connection. It uses flow control, clock correction, and byte alignment techniques to transmit 32-bit address events reliably over multiplexed serial connections. The setup has been tested using commercial Spartan6 FPGAs attaining a maximum event transmission speed of 75 Meps (Mega events per second) for 32-bit events at a line rate of 3.0 Gbps. Full HDL codes (vhdl/verilog) and example demonstration codes for the SpiNNaker platform will be made available.
doi:10.1109/tbcas.2017.2717341 pmid:28809708 fatcat:hekyjsz6njdhbaqwuyfv5wlmfy