Protocol decode for PCI Express signals

The capability provides a link-layer protocol decode for up to four PCI Express signals annotated on the oscilloscope physical-layer waveform.

Combined with LeCroy's 8b/10b decode-annotation tool (a separate option), simultaneous symbol/primitive- and protocol-level understanding can be achieved.

For faster time to insight, all the standard maths, measure, cursor, zoom and other analysis tools available in the oscilloscope may be used concurrently.

The PCI Express Decode Annotation capability has application for all versions of PCI Express.

It is especially helpful for the PCI Express Gen 3.0 standard, where new silicon physical-layer (PHY) links are beginning to be validated before the standard has been finalised.

By providing the decoded information as an annotation on the physical-layer waveform within the oscilloscope, the protocol and physical-layer information is synchronised and permits easy scrolling and review of the captured data.

By showing the link-layer protocol decode and the physical-layer waveform simultaneously on the oscilloscope in PCI Express Gen 1.x and Gen 2.0 debug time can be decreased.

By providing a link-layer decode annotation on the oscilloscope, it is easier for engineers to implement this standard in their design and assess the relationship between the PCI Express traffic and control lines or other signals in their embedded control system.

The initial data rate for decoding may be set to the common 2.5, 5 or 8GT/s.

The decode algorithm recognises the different bit rates and decodes appropriately, and supports modes with and without scrambling enabled.

Advanced algorithms deconstruct the waveform into protocol information and then annotate the physical-layer waveform on the oscilloscope grid.

Decode annotation condenses or expands, depending on the timebase/zoom ratio setting.

Various portions of the protocol are colour coded for quick visual understanding of the protocol behaviour and easy visibility, even with long acquisitions.

Decoded information is shown in a tabular format.

Touching a specific frame index in the table or searching for a specific frame type automatically creates a zoom trace showing physical-layer detail along with expanded decode information.

Search supports compliance, EIEOS, EIOS, electrical idle/error, DLLP, logical idle, SKIP, TLP, TS1, TS2, unrecognised or any type of frame.

Engineers may easily display all TS1 frames by searching for the first and pressing 'next' to advance through successive frames.

Offline data analysis is made simple by exporting tabular data in .csv format and analysing the data later in Excel.