Visible to Intel only — GUID: jfw1710728055780
Ixiasoft
Visible to Intel only — GUID: jfw1710728055780
Ixiasoft
4.4.1. PCIe AXI-ST TX Interface (ss_tx_st)
The outbound packet towards the link is transmitted through this PCIe AXI-ST TX interface with separate header and data interfaces. These interfaces support up to 4 segments of 256-bits with a maximum of 2 Transaction Layer Packets (TLPs) per cycle.
For information on this interface, refer to Application Logic Guidelines for the AXI Streaming TX Interface in HIP Native Mode (R-Tile) section in the AXI Streaming Intel FPGA IP for PCI Express User Guide.
Interface clock: axi_st_clk
NUM_OF_SEG depends on the data width.
NUM_OF_SEG = DWIDTH / SEG_WIDTH
DWIDTH = NUM_OF_SEG * 256
- 1024 bits for Gen5 1x16.
- 512 bits for Gen5 2x8, Gen4 1x16, and Gen3 1x16.
- 256 bits for Gen4 2x8, and Gen3 2x8.
Signal Name | Direction | Description |
---|---|---|
app_ss_st_tx_tvalid | Output | Indicates that the source is driving a valid transfer. |
ss_app_st_tx_tready | Input | 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'.
|
app_ss_st_tx_tdata[DWIDTH-1:0] | Output | Data interface with configurable width specified by DATA_WIDTH parameter. Gen5 1x16 DWIDTH: 4 segments x 256 = 1024 |
app_ss_st_tx_tkeep[DWIDTH/8-1:0] | Output | A byte qualifier used to indicate whether the content of the associated byte is valid. The invalid bytes are allowed only during app_ss_st_tx_tlast cycle.
Note: The sparse tkeep is not allowed.
|
app_ss_st_tx_tlast | Output | Indicates End of Data/Command Transmission |
app_ss_st_tx_tuser_last_segment [NUM_OF_SEG-1:0] |
Output | Indicates the last segment of the packet on tdata bus. For a packet without data payload, this signal is asserted during the header cycle on tuser_hdr bus. |
app_ss_st_tx_tuser_hvalid [NUM_OF_SEG-1:0] |
Output | Indicates the tuser_hdr is valid in the respective segment. |
app_ss_st_tx_tuser_hdr[DWIDTH-1:0] | Output | Carries header format for the respective segment. For the bit positions and mapping, refer to Header Format section in the AXI Streaming Intel FPGA IP for PCI Express User Guide. |