The PXIe-6555 and PXIe-6556 digital waveform instruments are now on a path to end-of-life. If your application includes one or more of these modules, you may choose to migrate to the PXIe-6570 Digital Pattern Instrument or migrate to another digital waveform instrument depending on the features your application requires. Review the following sections to help you decide which migration path is best for your application.
Per-Pin Parametric Measurement Unit (PPMU) and Active Load
The PXIe-6555 and PXIe-6556 digital waveform instruments feature PPMU and active load functionality. Because these are the only digital waveform instruments with this functionality, applications requiring PPMU or active load should greatly consider migration to the PXIe-6570 digital pattern instrument.
Data Rates Beyond 100 Mbit/s
The PXIe-6555 and PXIe-6556 digital waveform instruments acquire and generate data based on a fixed sample clock with a maximum frequency of 200 MHz. The PXIe-6570 digital pattern instrument leverages a more robust timing solution based on vectors rather than samples, allowing flexible and extremely precise configuration of drive and compare edges. The minimum vector period for the PXIe-6570 is 10ns, which allows generation of a 100MHz clock using the return low or return high drive formats available. For data pins, it is more common to use a non-return drive format which results in up to 100Mbps (works well for single data rate interfaces up to 100MHz). For DDR (Dual Data Rate interfaces), data pins update just as frequently as clock pins, and therefore a 100MHz non-return drive format results in 50MHz DDR interfacing. In addition, there is currently one compare strobe in a 10ns period. This means the PXIe-6570 is limited to comparing data at 100Mbps compared to the 200Mbps comparison capabilities of the PXIe-6555/6 hardware. NI has plans to increase data rates of the PXIe-6570 in the near future, if this is a concern for your application, please reach out to your local NI representative. A more detailed explanation of the timing differences between digital waveform and digital pattern instruments can be found in the Samples to Timesets section later in this document.
DUTs with More Than 32 Pins
For an application synchronizing multiple PXIe-6555/6 instruments to interface with a DUT with greater than 32 pins, migration to the PXIe-6570 may require additional calibration steps to achieve cross-instrument pin alignment.
PXI Digital Waveform Instrument Options
The PXIe-6544 and PXIe-6545 are 32-pin, 100 MHz and 200 MHz digital instruments intended for interfacing with numerous standard voltage levels for single-ended interfaces. These instruments are capable of data deskew and data delays on a per-bank basis that enable interfacing with DUTs, protocol testing, and skew adjustments due to cables or other impairments.
The PXIe-6547 and PXIe-6548 are 32-pin, 100 MHz and 200 MHz digital waveform instruments capable of generation high voltage levels between 1.2 V and 3.3V and input protection up to 5 V. These cards also offer per-bank data delays and deskew that enable interfacing with DUTs, protocol testing, and skew adjustments due to cables or other impairments.
The table below compares the PXIe-6555/6 with the PXIe-6570 Digital Pattern Instrument and the PXIe-6544/5/7/8 Digital Waveform Instruments:
|Instrument Type||Digital Waveform||Digital Pattern||Digital Waveform||Digital Waveform|
|Number of Bidirectional Channels||24||32||32||32|
|Logic Levels and Range||-2V to 7V||-2V to 6V||1.2V, 1.5V, 1.8V, 2.5V, 3.3V||1.2V – 3.3V|
|Advanced Overvoltage Protection||No||Yes||No||No|
|Maximum Supported Data Rate||200 Mbps||100 Mbps||100 Mbps||200 Mbps||200 Mbps with DDR||400 Mbps with DDR|
|Supported Data Formats||Non-Return|
Return to Low
Return to High
Surround by Complement
|Supports Active Load|