在现有的PSTN 网络上构建了一个嵌入式终端平台,该平台基于RISC 架构ARM 处理 器S3C2440A,符合国际电联ITU-T 建议的H.324 协议。此系统平台在原有的MCU+DSP 的架构基础上提出一种纯基于RISC 架构的ARM 处理器的可视电话平台,该方案更加灵活, 可以用于现有的办公,家庭等环境。本文介绍了该系统的结构以及实现方法。 关键词:RISC 架构,S3C2440A,PSTN,H.324 Abstract:Build a embedded platform of the ARM920T core RISC CPU S3C2440, which can connected to PSTN networks. This pure RISC system comply with the ITU-T H.324, developed from the MCU+ASIC and the MCU+DSP architecture, is more flexible. The VideoPhone based on this system could be widely used in the office and the house. This article briefly introduce the architecture and Realization method. Keywords: RISC,S3C2440A,PSTN,H.324