You need to test, we're here to help.

You need to test, we're here to help.

27 February 2023

The Case for CAN XL in 10 Mbit/S In-vehicle Networks

CAN XL has recently emerged as a contender in the 10 Mbit/S in-vehicle network space, along with 10Base-T1S Automotive Ethernet. What does CAN XL bring to earn its place on the vehicle bus?

CAN XL builds upon the foundation of CAN and CAN FD, both protocols with a long history in the automotive industry. Figure 1 summarizes the characteristics of the three CAN variants.

Figure 1. A comparison of the characteristics of CAN, CAN FD and CAN XL.

CAN XL increases throughput with a Fast Mode bit rate of 20 Mbit/S in the data phase, while it operates at 1 Mbps in the arbitration phase (those fields other than data). Another feature contributing to the improved bandwidth of CAN XL is the increased data field maximum length of 2048 bytes compared to 64 bytes for CAN FD and 8 bytes for classic CAN.

20 February 2023

The Evolution of In-vehicle Network Architectures

The drive for fuel-efficient and safer vehicles opened the door to electronic control in vehicles, which in turn led to the deployment of In-vehicle Networks (IVN).  IVNs have become the backbone of modern vehicles. The volume of data flowing through these networks is increasing exponentially with demands for electric vehicles, advanced driver assistance systems (ADAS), radar, lidar, infotainment systems, cameras and vehicle-to-vehicle communications systems.  

To meet this need, the automotive industry—working with technology suppliers—has developed specialized communications protocols and application-specific extensions to existing network technologies, standardized under the aegis of organizations like ISO and IEEE, and it continues to investigate new topologies and protocols to improve performance, increase reliability and lower the costs of IVNs. Two recent developments have filled a longstanding gap in IVN architectures: CAN XL (up-to-20 Mbit/S extended length CAN) and 10Base-T1S (10 Mbit/S single-pair Ethernet), both of which operate in the 10 Mbit/S network space. What problems do these protocols solve and what opportunities do they present for IVN design?

13 February 2023

Making New PCIe 6.0 Transmitter Equalization Measurements with Your Oscilloscope

Figure 1. Transmitter equalization test results for preset Q1.

PCI Express® 6.0 achieves its 64-GT/s data rate, double that of PCIe® 5.0, by moving from non-return-to-zero (NRZ) signaling to four-level pulse-amplitude-modulation (PAM4) signaling. This results in the need for more complex algorithms for voltage and timing measurements.

The latest release of SDAIII software for Teledyne LeCroy oscilloscopes lets you easily measure response at different transmitter equalization presets to confirm that Tx EQ is achieving the specified levels prior to taking your DUT for compliance testing. The Tx EQ measurement feature works with NRZ signals and, if you have the additional SDAIII-PAMx option, with PAM3 and PAM4 signals, too.

Transmitter Equalization Coefficients and Presets Measurement

In PCIe 6.0, transmitter equalization measurements are performed on the new PAM4 Compliance Pattern signal using the AC method that was first introduced in PCIe 5.0.

08 February 2023

Removing Oscilloscope Noise from PCIe 6.0 Compliance Pattern Measurements

Figure 1. The new SDAIII-PCIE6 option offers
three methods for removing oscilloscope noise
from PCIe 6.0 Compliance Pattern measurements
as required by the standard.
The new SDAIII-PAMx and SDAIII-PCIE6 options for Teledyne LeCroy oscilloscopes enable you to quickly make new PCIe 6.0 noise measurements SNDR and RLM with the oscilloscope baseline noise removed, as required by the standard.

Here's a brief description of the three, proprietary noise removal methods from which you can choose.

Manual Method

Manual uses the specified amount of oscilloscope noise for the 𝜎scope variable in the SNDRnr formula (described in the last post). This method is useful if you have previously measured your oscilloscope baseline noise and know what value to enter.

06 February 2023

New PCIe 6.0 Compliance Pattern Measurements

PCI Express® 6.0 features significant changes from PCIe® 5.0. In particular, PCIe 6.0 achieves its 64-GT/s data rate, double that of PCIe 5.0, by moving from non-return-to-zero (NRZ) signaling to four-level pulse-amplitude-modulation (PAM4) signaling. Consequently, PCIe 6.0 requires some new test methodologies and patterns, including a new PAM4 Compliance Pattern that finds use in multiple measurements.

Figure 1. The new PCIe 6.0 Compliance Pattern signal. Click any image to enlarge.

The new Compliance Pattern is used for calculating signal to noise and distortion ratio (SNDR), as well as ps21TX (the package insertion loss) and the transmitter ratio of level mismatch (RLM). In addition, it is used to measure transmitter equalization coefficients.