The DMA supports up to 32 different interrupt source for MSI-X, which consists of a maximum of 16 usable DMA interrupt vectors and a maximum of 16 usable user interrupt vectors. The DMA has 32 MSI-X tables, one for each source (see MSI-X Vector Table and PBA (0x00–0xFE0)). For MSI-X channel interrupt processing the driver should use the Engine’s Interrupt Enable Mask for H2C and C2H (see H2C Channel Interrupt Enable Mask (0x90) or Table C2H Channel Interrupt Enable Mask (0x90)) to disable and enable interrupts.