Based on the analysis of features of DMAC and ESCC Z85230 in Z80182, data transmission of HDLC in DMA method is analyzed and the communication program code on HDLC protocol is given.

• 介绍Z80182的DMA控制器和Z85230多协议串行控制器特点的基础上,分析了HDLC的DMA方式数据传送过程,给出了HDLC下的存储器直接存取的通信程序代码。