Implementation of a Compact and Resource-Efficient 32-bit Microcontroller Based on RISC-V Steel on FPGA and ASIC

This paper presents the implementation and verification process of a 32-bit microcontroller using the open-source RISC-V Steel 32-bit processor on the FPGA DE2 development kit and ASIC implementation on 45nm CMOS technology. The main goal is to design a complete 32-bit microcontroller that functions effectively with its designated features. This design is distinguished by the integration of a program loading controller that directly transfers instructions to RAM via the SPI interface without the involvement of the CPU and system data bus. This approach reduces boot time and alleviates CPU workload, enhancing overall system efficiency. The RISC-V Steel processor utilizes the RV32I instruction set architecture, complemented by 4KB of RAM, a 1KB stack, and basic interfaces such as UART, SPI, GPIO, and a Timer. With a total power consumption of 13.52 mW at 100 MHz and an area of 380,339 µm², the proposed design presents an energy-efficient, low-power, and compact solution suitable for modern embedded systems and IoT applications.