This document defines the hardware specification of the embedded board BS903. BS903 board mainly uses Samsung S3C2440A, which is a multi-functional system on chip (system-on-chip), and the core processor is ARM920T. BS903 board is an industrial-grade embedded operating platform with powerful functions, low power consumption, high cost performance, strong security and real-time performance. It can be used in a variety of fields, especially suitable for developing high-performance handheld and portable intelligent devices or control terminals.