Visible to Intel only — GUID: hex1481130239383
Ixiasoft
Visible to Intel only — GUID: hex1481130239383
Ixiasoft
17.6.2. DMA Controller
The DMA has independent transmit and receive engines, and a CSR space. The transmit engine transfers data from system memory to the device port or MAC transaction layer (MTL), while the receive engine transfers data from the device port to the system memory. Descriptors are used to efficiently move data from source to destination with minimal Host CPU intervention. The DMA is designed for packet-oriented data transfers such as frames in Ethernet. The controller can be programmed to interrupt the Host CPU for situations such as frame transmit and receive transfer completion as well as error conditions.
The DMA and the Host driver communicate through two data structures:†
- Control and Status registers (CSR)†
- Descriptor lists and data buffers †