PCIe Compliance Testing

Teledyne LeCroy is the main supplier of protocol analyzers and exercisers to companies developing SSD and other similar storage products using the new NVMe, SATA Express and SCSI Express high-speed serial data standards. Protocol analyzers and exercisers are used by developers and validation engineers to directly record and examine data traffic on serial data communication links between devices and systems. This equipment enables developers to reduce debug and test schedules, lower engineering development costs on new products and meet aggressive time-to-market requirements.

	Title	Time
	NVMe Protocol Analysis Features for Storage Development and Test	36:27

As storage developers make the transition from legacy SAS and SATA protocol-based SSDs to the more advanced NVMe and SATA Express technologies, they are encountering limitations in available design and test tools including limited trace recording times and a lack of standardized analysis reports for PCIe-based storage. These two issues are significant for the newer technologies of NVMe and SATA Express due to the following:

• High performance SSD testing can require recording data traffic beyond a few minutes. This is not possible for many protocol analyzers due to limitations in their recording architectures.
• While some test tool suppliers have claimed support for the NVMe and SATA Express protocols, support for these protocols has remained minimal. This has hampered developer's productivity due to the use of reporting systems designed for the older technologies, which are not optimized for quality testing on NVMe and SATA Express products.

The Summit T34 protocol analyzer, specifically targeted at PCIe storage applications, now supports long trace recordings with a new NVMe Enhanced Mode. The Summit T34 can also be configured with up to 64 GB of trace recording memory. NVMe Enhanced Mode builds on and optimizes the existing deep buffer memory to allow users long recording time capability. Depending on the speed of the DUT (Device Under Test), the recording time can be maximized to up to several hours for a single trace capture. This feature is useful for tasks such as measuring performance or determining how well your Queue handling algorithms are functioning. An example of the metrics that are now available include the ability to measure the NVMe queue distribution over a sustained period of time. The ability to gather queue behavior for long periods helps driver and OS developers fine tune their applications and balance queue loads for optimized product performance.

With over a decade of experience in providing PCI Express, SAS/SATA and other serial data protocols with standardized error analysis and product performance reports, Teledyne LeCroy has now created an NVMe and SATA Express SSD Performance and Analysis capability. Trace Expert™, a new feature in the PCIe Protocol Suite, creates a detailed report that the SSD industry requires to obtain a common understanding of how their SSD or storage systems are operating and includes information on the necessary PCIe based components. Information such as NVMe queues, commands, doorbell and control registers and many other metrics are captured, analyzed and organized into a detailed report providing developers a comprehensive status document for their products including a wide range of performance statistics.

In addition to the standard storage protocols, all of our NVMe platforms also fully support, Trusted Computer Group (TCG), Single Root I/O Virtualization (SRIOV), Multi-Root I/O Virtualization (MRIOV) and Address Translation Services (ATS). A full list of capabilities, views and reports can be found on the product pages (listed below) for each of our analyzers.

NVMe over PCIe Specification Decoding and Analysis - NVMe Initialization Decoding
• Decode NVMe Commands
• Analyze NVMe Queues
• NVMe Multiple Pointer Based Transactions
• NVMe Power Management
• Extract the PCIe SSD Base Address automatically

Teledyne LeCroy offers an integrated and automated compliance testing system, approved by the PCI-SIG as a standard tool for Link and Transaction Layer Compliance testing for developers working with the PCIe 4.0 and PCIe 5.0 specification. This solution combines a Summit Z58 or Summit Z516 Exerciser and a PCI Express Test Platform (for testing End-Point devices) This system has been selected by the PCI-SIG as a standard test tool for PCI Express 4.0 and PCI Express 5.0 Link and Transaction Layer Compliance Testing.

Teledyne LeCroy also offers an integrated and automated validation testing system for PCI Express root complex and endpoint devices called LinkExpert. This test application presents you with full test coverage for both the Link Layer and Transaction Layer as specified by the PCI SIG for add-in-card and system devices. The Validation scripts leverage Teledyne LeCroy's Summit Exerciser and Analyzer Platforms to achieve the highest performance possible. Tests are available for x1, x2, x4, x8, and x16 link widths.

The LinkExpert Software is packaged with and available at no cost to users of the Summit systems.

The LinkExpert Software package allows you to:

• Prepare your add-in-card or system board to pass the Validation tests from the PCI-SIG.
• Display a log window that shows you the test events leading up to the pass or fail of an individual Validation test.
• Identify errors, including type, and shows you where the errors occurs in the trace, and includes hyperlinks back to that trace.
• Automatically run tests and save log files.
• Error logs and their corresponding failure in the protocol trace are saved together for product development records.
• Modify the Validation tests and generate test scenarios through the script editor.

Some examples of Link Layer test scripts include:

• Test 41-20 ReserveFieldsDLLPReceive Test
  • Verify that the DUT ignores reserved fields in an ACK DLLP
• Test 52-160 UndefinedDLLPEncoding Test
  • Verify that the DUT silently drops any DLLP with undefined encoding and no error is associated with it.
• Test 52-170 WrongSeqNuminAckDLLP Test
  • Verify that the DUT drops any ACK DLLP that does not have a sequence number corresponding to an unacknowledged TLP and logs a BAD DLLP error associated with the port.
• Test 52-10 RetransmitOnNak
  • The intent of this test is to ensure that a DUT will retransmit a transaction for which a NAK has been issued