DESIGN AND RTL VERIFICATION OF A RECONFIGURABLE TRI-PROTOCOL COMMUNICATION BRIDGE FOR UART, SPI, AND I²C INTERFACES

Abstract

Modern embedded systems, Internet of Things (IoT) devices, industrial automation platforms, and System-on-Chip (SoC) architectures frequently employ multiple communication protocols to connect heterogeneous peripherals and processing units. Among the most widely adopted serial communication standards are Universal Asynchronous Receiver Transmitter (UART), Serial Peripheral Interface (SPI), and Inter-Integrated Circuit (I²C), each offering distinct advantages in terms of speed, complexity, and communication topology. However, interoperability among devices utilizing different protocols remains a significant challenge, often requiring software-based conversion mechanisms that introduce latency, processing overhead, and increased power consumption. To address these limitations, this paper presents the design and RTL verification of a reconfigurable Tri-Protocol Communication Bridge capable of enabling seamless data transfer among UART, SPI, and I²C interfaces. The proposed architecture employs a Source Detection Unit, Source Multiplexer, FIFO-based buffering mechanism, and a centralized Finite State Machine (FSM) controller to manage protocol selection, data routing, and transmission control. A Communication Operation Selection Encoding (COSE) scheme is introduced to dynamically support six protocol conversion modes, including UART-toSPI, UART-to-I²C, SPI-to-UART, SPI-toI²C, I²C-to-UART, and I²C-to-SPI communication paths. The FIFO buffer provides reliable temporary storage and rate matching between heterogeneous protocols operating at different transmission speeds. The complete system is modeled using Verilog Hardware Description Language (HDL) and verified through comprehensive RTL simulation. Simulation results demonstrate correct protocol conversion, reliable data buffering, deterministic control operation, and efficient communication routing. The proposed architecture offers a scalable, modular, and hardware-efficient solution for multi-protocol communication systems and is particularly suitable for embedded controllers, IoT gateways, industrialmonitoring systems, and smart electronic devices requiring interoperability among diverse serial communication interfaces