User-Level DMA From the VME Bus

User-Level DMA From the VME Bus

The Challenge L, Challenge XL, and Onyx systems and their Power versions contain a DMA engine that manages DMA transfers from VME devices, including VME slave devices that normally cannot do DMA.

The DMA engine in these systems can be programmed directly from code in a user-level process. Software support for this facility is contained in the udmalib package.

For more details of user DMA, see Chapter 4, "User-Level Access to VME and EISA" and the udmalib(3) reference page.