Design of a Multi-Channel BiSS-C Asynchronous Acquisition and Synchronous Transmission Interface Based on FPGA

Multi-channel synchronous data transmission interfaces are increasingly required to deliver higher accuracy, reliability, and cost efficiency for displacement measurement in industrial ultra-precision equipment and advanced manufacturing. The bidirectional serial synchronous continuous (BiSS-C) protocol is widely used for high-precision sensor data transfer due to its advantages of fast transmission speed, anti-interference capability, and low implementation cost. However, existing methods cannot effectively address data acquisition errors and decoding timing mismatches caused by inconsistent line delays between channels. This paper proposes a design for a multi-channel BiSS-C asynchronous acquisition and synchronous transmission interface based on FPGA. The proposed interface employs an asynchronous data acquisition mechanism based on majority voting to dynamically adapt to line delay and ensure reliable data acquisition. A barrier synchronization module is designed to eliminate the difference in decoding progress between channels and achieve synchronous output. Experimental verification through a laser interferometer displacement measurement system demonstrates that the proposed interface operates without CRC errors under multi-channel parallel operation. It supports a maximum clock frequency of 10 MHz and achieves a control cycle frequency above 10 kHz. The engineering practicality of the interface is further verified through displacement measurement experiments.