基于ARM的ZDMA传输设计与实现

Design and Realization of ZDMA Transfer Based on ARM

DMA技术是一种由DMA控制器控制的存储器与外部设备或存储器之间大数据量传输的技术,具有传输速度高、CPU额外开销小的优点。ARM微处理器是32位RISC处理器,具有低功耗、高性价比等特点。文中介绍了一种使用ARM在外设与系统Memory之间实现DMA On-the-fly模式传输的设计方法,硬件部分基于S3C44B0X的ARM7 TDMI微处理器,通过一个ZDMA控制器实现ARM7与系统外设间的通信,将CPU从繁杂的I/O事务中解放出来,解决了原有系统中因采用中断和轮询方式进行传输而导致的系统瓶颈,使得整个系统的速度与传输效率大大提升。

DMA is a means of having a peripheral device control a processor＇s memory bus directly.DMA permits the peripheral to transfer data directly to or from memory without having each byte（or word） handled by the processor.Thus DMA enables more efficient use of interrupts or poll,increases data throughput,and potentially reduces hardware costs by eliminating the need for peripheral.ARM microprocessor is a 32 bits RISC processor with low power,high cost performance.Introduce a design method of realizing On-the-fly DMA transmission in peripheral and memory based on ARM,with the choice of ARM7 TDMI of S3C44B0X realize data transmission between the ARM7 and the peripheral,and also release the CPU from the miscellaneous work of I/O,solve the bottleneck of the original system,improve the speed and transmission efficiency of the whole system.