DSP Impletation Of Networked Video Communication Terminals

With the development of VLSI and imbedded technologies, embedded video communication terminals are becoming the main steam of video communication products.The thesis developed an embedded platform for the networked video communication terminals and implemented the hardware modules of video capturing, encoding-decoding and real-time network communicating based on TI's digital media DSP DM642.DM642 features plenty of on-chip resources and thus needs simple peripheral interface circuits. The DSP-cored audio-video processing system developed includes the main modules such as DM642 smallest system, audio-video acquisition and codec, logic control, ethernet interface and other peripheral modules.To minimize the multi-layer PCB noise, the PCB layout was considered carefully along with the reasonable layer assignmen, suitable division of power layer and ground layer according to the multiple power references inherent in the system. When routing, the main signal tracks were delt with as shortly and branchlessly as possible. The power pins were decoupled perfectly to lower the electromagnetic disturbance.The softeare running on the hardware platform was implemented based on the BSL (Board Support Library) and the CSL (Chip Support Library). The software structure was layered, including CSL, BSL, device drivers and application software layers. CSL and BSL provide the basic APIs to control the hardware. The device drivers such as video port driver were designed accoding to TI's two-layer driver model - class/mini driver model. The upper...