When the DMA Descriptor Controller is embedded in the Avalon-MM DMA bridge, it drives this
information on an internal conduit interface.
Figure 7-9: Block Diagram for Internal Descriptor Controller
PCIe Avalon-MM DMA Bridge
Hard IP for PCIe Using Avalon-MM Interface
Altera FPGA
Qsys System
with Internal Descriptor Controller
Memory
Read DMA
Write DMA
Hard IP
for PCIe
RX Master
TX Slave
DMA
Descriptor
Controller
Avalon-MM Burst
Master 256 Bits
Avalon-MM Burst
Master 256 Bits
Avalon-MM Master
Avalon-MM Slave Single DWORD
Avalon-ST Control/Status
Avalon-ST
256 Bits
FIFO
Internal Conduit
Figure 7-10: Block Diagram for External Descriptor Controller
Altera FPGA
Memory
Read DMA
Write DMA
Hard IP
for PCIe
RX Master
TX Slave
DMA
Descriptor
Controller
Avalon-MM Burst Master 256 Bits
Avalon-MM Master 256 Bits
Avalon-MM Master Single DWORD
Avalon-MM Slave Single DWORD
Avalon-ST Control/Status
Avalon-ST
256 Bits
PCIe Avalon-MM
DMA Bridge
Hard IP for PCIe Using Avalon-MM Interface
with External Descriptor Controller
Qsys System
The Read DMA transfers data from the PCIe address space to Avalon-MM address space. It issues
memory read TLPs on the PCIe link. It writes the data returned to a memory in the Avalon-MM address
space. The source address is the address for the data in the PCIe address space. The destination address is
in the Avalon-MM address space.
7-16
DMA Descriptor Controller Registers
UG-01145_avmm_dma
2015.11.02
Altera Corporation
Registers
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