Architecture - 4.0 English

QDMA Subsystem for PCI Express Product Guide (PG302)

Document ID
PG302
Release Date
2022-05-20
Version
4.0 English

The Root Port Model consists of these blocks:

  • dsport (Root Port)
  • usrapp_tx
  • usrapp_rx
  • usrapp_com (Verilog only)

The usrapp_tx and usrapp_rx blocks interface with the dsport block for transmission and reception of TLPs to/from the Endpoint Design Under Test (DUT). The Endpoint DUT consists of the Endpoint for PCIe and the PIO design (displayed) or customer design.

The usrapp_tx block sends TLPs to the dsport block for transmission across the PCI Express Link to the Endpoint DUT. In turn, the Endpoint DUT device transmits TLPs across the PCI Express Link to the dsport block, which are subsequently passed to the usrapp_rx block. The dsport and core are responsible for the data link layer and physical link layer processing when communicating across the PCI Express logic. Both usrapp_tx and usrapp_rx use the usrapp_com block for shared functions, for example, TLP processing and log file outputting. Transaction sequences or test programs are initiated by the usrapp_tx block to stimulate the Endpoint device fabric interface. TLP responses from the Endpoint device are received by the usrapp_rx block. Communication between the usrapp_tx and usrapp_rx blocks allow the usrapp_tx block to verify correct behavior and act accordingly when the usrapp_rx block has received TLPs from the Endpoint device.