Re: question for programming the DMA controller

["Weng Tianxiang" <wtx@umem.com>]

Hi Zhang,

1. You have to allocate space using BARx in configuration space to be used for DMA parameters;

2. CPU or software writes DMA command parameters into the parameter space;

3. The space has a GO bit; when the bit is set to 1, DMA engine starts a DMA operation using parameters set by the software.

 

Weng Tianxiang
Micro Memory Inc.
9540 Vassar Av.
Chatsworth, CA 91311
Phone: 818-998-0070, Fax: 818-998-4459

----- Original Message -----

From: Zhang Jun

To: pci-sig@znyx.com

Sent: Tuesday, February 06, 2001 9:25 PM

Subject: question for programming the DMA controller

I am studing to design a DMA controller. But I don't know when the CPU can program the DMA controller before a DMA transfer can begin. How the CPU know that it is the time to program the DMA controller. Please give me a help.

Thanks.