The Studies And Design On Embedded TCP/IP Ethernet Controller

Embedded system is a specific computer system that used to implement special functions. Based on microelectronics, control technique, computer technology and mechanics of communication, embedded system serves for applications to fulfill the demands of functions, cost, area and power. Internet embedded system is a combination between Internet techniques and embedded system. In order to obtain the best proportion between efficiency and cost, rapid development of integrate chip techniques has driven the system into System-On-Chip (SOC) age.By using hardware/software co-design platform-based SOC design method, a novel embedded network controller based on TCP/IP protocols is implemented.The bottleneck of embedded system is the original 8051 core. By analyzing the original 8051-core design, we can find that there is hugely wasted in the 12 clock cycles. A firmware downloadable and one-cycle pipelined architecture of RISC CPU IP core has been designed. The instruction executing speed of this RISC CPU is 10 times fast than classical 8051 MCU. Firmware update is supported in this RISC core. According to IEEE802.3 protocol, a media access controller (MAC) based on TCP/IP protocols is implement. Direct Memory Access (DMA) technique has been used for high-speed data transport between SRAM memory and data buffers, which accelerates the speed of Ethernet transceiver. Interface technology is important in SOC design. This paper has declared the arbitration between MCU and MAC, FLASH access circuit and so on. The detailed principles of design for test (DFT) techniques, chip synthesis are discussed. Meanwhile, the know-how to firmware of embedded network controller SOC chip is discussed in detail. The boot ROM programming and TCP/IP protocols are also described.The embedded network controller SOC chip is in 1st silicon's 0.25-micron CMOS process, the gates of this manufactured chip around 200,000. The chip's area is 4800 x 4578μm2. We can rough estimate that the cost of this SOC chip is about 1$. Using SmartBit tester, we tested the system's throughput. Through emulation, we testified that the maximum throughput of Ethernet packets is up to 7 Mbps, the maximum throughput of UDP packets is up to 5.8 Mbps, and the maximum throughput of TCP packets is up to 3.4 Mbps. It showed that using this embedded system could easily transmit basic voice and video signals through Ethernet. Therefore, using the only one chip could realize that many electronic devices access to the Internet directly and get high performance. Obviously, this is a low cost but high performance embedded network controller.