17–10
Chapter 17: Debugging
Use Third-Party PCIe Analyzer
Arria V GZ Hard IP for PCI Express
November 2012
Altera Corporation
f
The
PHY Interface for PCI Express Architecture
specification is available on the Intel
website (
Use Third-Party PCIe Analyzer
A third-party logic analyzer for PCI Express records the traffic on the physical link
and decodes traffic, saving you the trouble of translating the symbols yourself. A
third-party logic analyzer can show the two-way traffic at different levels for different
requirements. For high-level diagnostics, the analyzer shows the LTSSM flows for
devices on both side of the link side-by-side. This display can help you see the link
training handshake behavior and identify where the traffic gets stuck. A traffic
analyzer can display the contents of packets so that you can verify the contents. For
complete details, refer to the third-party documentation.
BIOS Enumeration Issues
Both FPGA programming (configuration) and the initialization of a PCIe link require
time. There is some possibility that Altera FPGA including a Hard IP block for PCI
Express may not be ready when the OS/BIOS begins enumeration of the device tree.
If the FPGA is not fully programmed when the OS/BIOS begins its enumeration, the
OS does not include the Hard IP for PCI Express in its device map. To eliminate this
issue, you can do a soft reset of the system to retain the FPGA programming while
forcing the OS/BIOS to repeat its enumeration.
txcompl0
[42]
[202]
This signal forces the running disparity to negative in
compliance mode (negative COM character).
txelecidle0
[41]
[201]
This signal forces the TX output to electrical idle.
txdetectrx0
[40]
[200]
This signal tells the PHY layer to start a receive detection
operation or to begin loopback.
txblkst0
[39]
[199]
For Gen3 operation, indicates the start of a block.
txsynchd0[1:0]
[38:37]
[198:197]
For Gen3 operation, specifies the block type. The
following encodings are defined:
■
2'b01: Ordered Set Block
■
2'b10: Data Block
txdataskip0
[36]
[196]
For Gen3 operation. Allows the MAC to instruct the TX
interface to ignore the TX data interface for one clock
cycle. The following encodings are defined:
■
1’b0: TX data is invalid
■
1’b1: TX data is valid
txdatak0[3:0]
[35:32]
[195:192]
These signals show the data and control being
transmitted from the Arria V GZ Hard IP for PCI Express
to the other device.
txdata0[31:0]
[31:0]
[191:160]
Table 17–3. PIPE Interface Signals (Part 3 of 3)
Signal Name
Lane 0
Lane 1
Description