Can AD9910 generate square and triangular waves?

Can AD9910 generate square and triangular waves?

I use the AD9910 Eval Board and the AD9910 Evaluation Software.
I want to make square wave and triangular wave using DRG Modulation and RAM Modulation.
Use an internal 25Mhz crystal.

How do I configure the AD9910 Evaluation Software to create square and triangular waves?

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  • 0
    •  Analog Employees 
    on Nov 3, 2016 4:54 PM

    Actually, the AD9910 can generate almost any kind of wave form. The DRG, RAM and Parallel Port can drive any of the DDS's three control parameters: frequency, phase or amplitude. Most, but not all, of the full flexibility of the AD9910 wave form generation capability is available through the Evaluation Board software.

    You can generate triangle data via the DRG by setting the No Dwell bits. This causes the DRG to continuously ramp up and down between the programmed start and stop limits, thereby generating a triangular sequence of data. If the DRG destination is set for "amplitude", then the triangle data applies to the DDS's amplitude parameter. Because you want to generate a triangular output signal as opposed to applying triangular modulation to a carrier, you need to set the DDS frequency to 0 (DC) via the FTW register. The net result is a triangular wave with amplitude and period governed by the DRG.

    You can generate a square wave the same way, except that the DRG step size must be as large as the difference between the start and stop values. This causes the DRG to "ramp" up in a single step and back down in a single step, thereby producing alternating high and low values (i.e., a square wave).

    If you can drive the Parallel Data Port from an external digital generator, then you can produce completely arbitrary waveforms. Of course, this requires some external equipment and configuring the Eval. Bd. to accept external data at the Parallel Data Port (i.e., disable the FIFO).

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  • 0
    •  Analog Employees 
    on Nov 3, 2016 4:54 PM

    Actually, the AD9910 can generate almost any kind of wave form. The DRG, RAM and Parallel Port can drive any of the DDS's three control parameters: frequency, phase or amplitude. Most, but not all, of the full flexibility of the AD9910 wave form generation capability is available through the Evaluation Board software.

    You can generate triangle data via the DRG by setting the No Dwell bits. This causes the DRG to continuously ramp up and down between the programmed start and stop limits, thereby generating a triangular sequence of data. If the DRG destination is set for "amplitude", then the triangle data applies to the DDS's amplitude parameter. Because you want to generate a triangular output signal as opposed to applying triangular modulation to a carrier, you need to set the DDS frequency to 0 (DC) via the FTW register. The net result is a triangular wave with amplitude and period governed by the DRG.

    You can generate a square wave the same way, except that the DRG step size must be as large as the difference between the start and stop values. This causes the DRG to "ramp" up in a single step and back down in a single step, thereby producing alternating high and low values (i.e., a square wave).

    If you can drive the Parallel Data Port from an external digital generator, then you can produce completely arbitrary waveforms. Of course, this requires some external equipment and configuring the Eval. Bd. to accept external data at the Parallel Data Port (i.e., disable the FIFO).

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