Developing Drivers with the Windows® Driver Foundation

DMA-Specific Device Information

Writing a driver for a DMA device is somewhat more complicated than writing a driver for a most other types of devices. The job is easier if you understand the design details of the device and how the driver can control it before you begin to write the driver. Table 17-1 shows a checklist of the required design information.

Table 17-1. DMA-Specific Device Information

Device information	Possible values
DMA design type	Packet-based, common-buffer, or hybrid
Maximum addressing capability	32-bit, 64-bit, or other
Hardware scatter/gather support	Yes or no
Maximum transfer length per DMA operation	Number of bytes
Buffer alignment requirement	None, word, longword, or quadword

The information in Table 17-1 is important in determining ...