AXI Multichannel DMA Intel® FPGA IP for PCI Express* User Guide

ID 817911
Date 4/07/2025
Public

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5.4.3.2. AXI-MM Read Channel (D2H)

The AXI-MM Read channel is used to read D2H DMA data from the external AXI-MM responder. This port is capable of reading a maximum of 512 bytes of data per AXI-MM transaction.

Table 45.  AXI-MM Read Channel (D2H)
Signal Name Direction Description
Read Address Channel
dma_axi_mm_arvalid Output Read address valid. This signal indicates that the channel is signaling valid read address and control information.
dma_axi_mm_arready Input Read address ready. This signal indicates that the slave is ready to accept an address and associated control signals.
dma_axi_mm_arid[3:0] Output Transaction ID for the Read. Depends on the number of outstanding requests (default is 4 outstanding requests).
dma_axi_mm_araddr[63:0] Output Read address. The read address gives the address of the first transfer in a read burst transaction.
dma_axi_mm_arlen[7:0] Output Burst length. The burst length gives the exact number of transfers in a burst. This information determines the number of data transfers associated with the address.
dma_axi_mm_arsize[2:0] Output Burst size. This signal indicates the size of each transfer in the burst.
dma_axi_mm_arburst[1:0] Output Burst type. The burst type, along with the burst size information, determines how the address is calculated for each transfer within the burst. AXI MCDMA supports only INCR burst type.
dma_axi_mm_arprot[2:0] Output

Protection type. This signal indicates the privilege and security level of the transaction, and whether the transaction is a data access or an instruction access (not used).

dma_axi_mm_arlock Output Lock type. Tied to '0'.
Read Data Channel
dma_axi_mm_rvalid Input Read valid. This signal indicates that the channel is signaling the required read data.
dma_axi_mm_rready Output Read ready. This signal indicates that the master can accept the read data and response information.
dma_axi_mm_rlast Input Read last. This signal indicates the last transfer in a read burst.
dma_axi_mm_rid[3:0] Input Read ID tag. Depends on number of outstanding requests. Default is 4 outstanding.
dma_axi_mm_rdata

x16: [1023:0]

x8: [511:0]

x4: [255:0]

Input Read data. Data bus width varies based on the PCIe link width.
dma_axi_mm_rresp Input Read response. This signal indicates the status of the read transfer. EXOKAY is not supported.