基于MPC8280的ATM适配与DMA驱动设计的研究

Implementation of DMA channel and ATM adapter based on MPC8280

在TD-SCDMA网络中,ATM采用AAL5和AAL2来完成ATM数据的适配处理。由于目前大部分的网络处理器都只支持AAL5,不适应TD网络测试仪的应用;而且为了满足仪表对海量的TD网络数据进行实时的处理,DMA的传输模式以其特有的优点"进行数据传递时不需要CPU的参与"成为了设计的首选。针对此本文提出了采用PowerPC8280来实现AAL2适配,以及如何利用基于PCI的DMA传输完成上层应用与底层硬件的数据交互。实际使用表明,文中提出的方案能够对AAL2适配和DMA传输进行正确处理,达到了TD-SCDMA网络测试的要求。

In ID-SCDMA networks, ATM adopts AAL5 and AAL2 to process ATM data. Due to present networks processor being only applicable for AAL5, which is not suitable for TD network testing, and the requirement for real time processing a great deal of TD network data, DMA had become the prior choice based on the unique characteristic of data transmission without CPU. This paper introduces a new PowerPC8280-based AAL2 data adapting and a PCI- based DMA which dedicate at the data interact between application layer and physical layer. Application proves that the project is suitable for AAL2 adapting and DMA transmission and can meet the requirement of ID-SCDMA network tester.