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

ID 817911
Date 7/22/2024
Public
Document Table of Contents

4.4.2. PCIe AXI-ST RX Interface (ss_rx_st)

The packets from the link is received on this interface with separate header and data interfaces. These interfaces support up to 4 segments of 256-bits with a maximum of 3 Transaction Layer Packets (TLPs) per cycle.

For information on this interface, refer to the AXI Streaming Intel FPGA IP for PCI Express User Guide.

Interface clock: axi_st_clk

NUM_OF_SEG = 4

DWIDTH = NUM_OF_SEG * 256=1024

Table 14.  PCIe AXI-ST RX Interface
Signal Name Direction Description
ss_app_st_rx_tvalid Input

Indicates that the source is driving a valid transfer

app_ss_st_rx_tready Output

Indicates that the sink can accept a transfer in the current cycle.

Note: The readyLatency parameter defined in Avalon specification is supported. By default, the value is '0'.
ss_app_st_rx_tdata[DWIDTH-1:0] Input

Data interface with configurable width specified by DWIDTH parameter.

ss_app_st_rx_tkeep[DWIDTH/8-1:0] Input

A byte qualifier used to indicate whether the content of the associated byte is valid.

The invalid bytes are allowed only during the ss_app_st_rx_tlast cycle.

Note: The sparse ss_app_st_rx_tkeep is not allowed.
ss_app_st_rx_tlast Input

Indicates End of Data/ Command Transmission.

Note: tlast may seem redundant with the tuser_last_segment. However, tlast can be used by the front-end layer of the AXI BFM/routing fabric that does not deal with the decoding of the multipacket data.
ss_app_st_rx_tuser_last_segment[NUM_OF_SEG-1:0] Input

Indicates Packet End position on tdata bus.

ss_app_st_rx_tuser_hvalid[NUM_OF_SEG-1:0] Input

Indicates the ss_app_st_rx_tuser_hdr is valid in the respective segment.

ss_app_st_rx_tuser_hdr[DWIDTH-1:0] Input

tuser_hdr is in Power User mode header format