F-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide

ID 683140
Date 8/19/2024
Public
Document Table of Contents

8.1.1.2. Signal Tap II Logic Analyzer

Using the Signal Tap II Logic Analyzer, you can monitor the following top-level signals from the F-Tile Avalon® -ST IP for PCI Express to confirm the failure symptom for any port type (Root Port, Endpoint or TLP Bypass) and configuration (Gen4/Gen3).

Table 114.  Top-Level Signals to be Monitored for Debugging
Signals Description Expected Value for Successful Link-up
p#_pin_perst_n where # = 0, 1, 2, 3

Active-low asynchronous output signal from the PCIe Hard IP. It is derived from the pin_perst_n input signal.

1'b1
p#_reset_status_n where # = 0, 1, 2, 3

Active-low output signal from the PCIe Hard IP, synchronous to coreclkout_hip.

Held low until pin_perst_n is deasserted and the PCIe Hard IP comes out of reset, synchronous to coreclkout_hip.

When port bifurcation is used, there is one such signal for each Avalon® -ST interface.

1'b1
ninit_done

Active-low output signal from the Reset Release Intel FPGA IP. High indicates that the FPGA device is not yet fully configured, and low indicates the device has been configured and is in normal operating mode.

For more details on the Reset Release Intel FPGA IP, refer to https://www.intel.com/content/www/us/en/programmable/documentation/prh1555609801770.html

1'b0
p#_link_up_o where # = 0, 1, 2, 3

Active-high output signal from the PCIe Hard IP, synchronous to coreclkout_hip.

Indicates that the Physical Layer link is up.

1'b1
p#_dl_up_o where # = 0, 1, 2, 3

Active-high output signal from the PCIe Hard IP, synchronous to coreclkout_hip.

Indicates that the Data Link Layer is active.

1'b1
p#_ltssm_state_o where # = 0, 1, 2, 3

Indicates the LTSSM state, synchronous to coreclkout_hip.

6'h11 (S_L0)

Negotiated link speed using the Transaction Layer Configuration Output interface (tl_cfg):

p#_tl_cfg_add_o[4:0]

p#_tl_cfg_ctl_o[15:12]

p#_tl_cfg_func_o[2:0]

Use the Transaction Layer Configuration Output interface (tl_cfg) to monitor the auto-negotiated link speed.

p#_tl_cfg_add_o[4:0] = 5'h05

p#_tl_cfg_ctl_o[15:12] =
  • 4’h01 (Gen1)
  • 4’h02 (Gen2)
  • 4’h04 (Gen3)
  • 4’h08 (Gen4)
p#_tl_cfg_func_o[2:0] (NA for p2 and p3) =
  • 3’b000: PF0
  • 3'b001: PF1, etc.

Negotiated link width using the Transaction Layer Configuration Output interface (tl_cfg):

p#_tl_cfg_add_o[4:0]

p#_tl_cfg_ctl_o[5:0]

p#_tl_cfg_func_o[2:0]

Use the Transaction Layer Configuration Output interface (tl_cfg) to monitor the auto-negotiated link width.

p#_tl_cfg_add_o[4:0] = 5'h1C

p#_tl_cfg_ctl_o[5:0] =
  • 6’h01 (x1)
  • 6’h02 (x2)
  • 6’h04 (x4)
  • 6’h08 (x8)
  • 6'h10 (x16)