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SPI Digital Waveform Library

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Please provide feedback, comments and questions on the SPI Digital Waveform reference library in this thread.

 

- David

 

(posted by Christian on behalf of David)

authored by
Christian L, CLA
Principal Development Manager - Partner Program
Applications Engineering Senior Manager - Data Acquisition, Control, and Real-Time Test
National Instruments - Austin, TX

  
Message 1 of 190
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Hello,

 

I'm using this library to generate the SPI waveforms. How do I output/input the signal waveforms (CS, MOSI, MISO, SCLK) using a PXI-6509 DIO? I've built individual channels with , each one to handle one signal. However, I could not output them simultaneously, so that all the timings configured using the library are kept. How was the intended method to do this?

 

Thanks,

Su Gin

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Message 2 of 190
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I forgot to add: With the VI shown in the image, I'm getting a varying amount of delay between the signals.

 

Thanks,

Su Gin

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Message 3 of 190
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Hi sugeo -

 

You'll only be able to use the SDW waveform with a clocked digital I/O device.  Software-timed I/O devices like the 6509 can't generate or acquire the data deterministically, nor can they toggle lines simultaneously.  Devices that can clock their digital I/O include the M-Series DAQ (62xx) and 653x, 654x, and 655x High-Speed Digital I/O.

David Staab, CLA
Staff Systems Engineer
National Instruments
Message 4 of 190
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Hello David,

 

Thanks for clearing that up.  I would have to generate/acquire one bit from each line and move through all the lines sequentially until I have all my bits, right? Such as described by Tom in Message 16 of 25 in http://forums.ni.com/ni/board/message?board.id=70&thread.id=7192&page=2?

Would generating SPI waveforms on PXI-6723 be any different?I noticed it has some counter pins and digital routing ability.

 

Regards,

Su Gin

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Message 5 of 190
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Hi Su Gin -

 

Tom's example approximates a SPI exchange using software-timed control of static DIO pins.  The SDW was designed around the assumption that a device's DIO are controlled by a free-running clock, so its waveforms won't work with his programming model.

 

The 6723's DIO are also static, and so that device can't be used with the SDW.  Looking through the NI Example Finder, I see that the examples Correlated Dig Write With Counter and Correlated Dig Read With Counter list support for the devices that can control their DO and DI pins (respectively) with a free-running clock.  You may want to use that as a rubric for which DAQ devices can be used with the SDW.

 

(Note that the DAQmx-based HSDIO devices -- 653x -- aren't listed because their programming model is different.)

David Staab, CLA
Staff Systems Engineer
National Instruments
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Message 6 of 190
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Hi,

 

Can you provide examples integrating these SPI waveforms with DaqMxRead/Write ? I am using 4 separate DIO lines of PCI 6229

 

connected  to the Master Device(the device is generating the clock).I should both read and write data to that device through SPI

Message 7 of 190
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Hi

 

We have an ASIC out to fab and we're doing its evaluation planning and are in the phase where we are purchasing all the products needed to evaluate it. The digital portion of the ASIC can be communicated via an SPI, so we'd like to have a set-up where we can give inputs to the SPI along some other analog inputs and be able to read the digital outputs(on SPI again) and analog outputs. I know that Labview accompanied with compatible hardware will be able to do it, but not sure exactly as to what hardware we should resort to. I'm completely new to this Labview/accompanying hardware and any help would be hihgly appreciated. Thanks.

 

Priyatham.

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Message 8 of 190
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hello,

    can i use the SPI DIgital Waveform Library on PCI-6251? if can,How do I output/input simultaneously the signal waveforms (CS, MOSI, MISO, SCLK) with  PCI-6251 digital I/O? IF can't, can i simulate the SPI Bus (to high-speed communication) with PCI-6251?

 

  thanks

  view

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Message 9 of 190
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Hi Priyatham -

 

NI has an entire fleet of products capable of helping you with your ASIC test.  Figuring out which ones are appropriate for your performance and cost tradeoffs usually requires that we understand a fair amount of the details in your system. I recommend contacting your local NI sales person or office for help selecting the right products in a confidential discussion.

David Staab, CLA
Staff Systems Engineer
National Instruments
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Message 10 of 190
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