Rev 15 Feb 2013 14:39 | Page 25
Programming Method:
HW – selects the control pins to implement the register selection, reset, and DAC power-down
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functions.
SW – selects the control bits to implement the register selection, reset, and DAC power-down
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functions.
Frequency control:
F1 – FREQ1 register is used in the phase accumulator.
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F0 – FREQ0 register is used in the phase accumulator.
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Phase control:
P1 – PHASE1 register data is added to the output of the phase accumulator.
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P0 – PHASE0 register data is added to the output of the phase accumulator.
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IOUT Output:
Ramp – Triangle signal at the output.
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Sin – Sinusoidal signal at the output.
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HW Pins:
F1 / F0 – This pin controls which frequency register, FREQ0 or FREQ1, is used in the phase
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accumulator.
P1 / P0 – This pin controls which phase register, PHASE0 or PHASE1, is added to the phase
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accumulator output.
Sleep: When this pin is high, the DAC is powered down.
Reset: This pin resets the appropriate internal registers to 0.
Section C is used to load values in the frequency and phase registers. A frequency value is set using
the corresponding dial and slider controls. The dial sets the number of the digit to be modified and the
slider sets the value of the selected digit. For example in order to set the value of 1234 Hz the
following steps have to be performed (not necessarily in the listed order):
put the dial to position 0 and move the slider to 4;
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put the dial to position 1 and move the slider to 3;
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put the dial to position 2 and move the slider to 2;
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put the dial to position 3 and move the slider to 1.
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Section D is used to set or clear the bits which affect the signal from the SIGN BIT OUT output.
Sign Bit Output Options:
Enable / Disable – enables / disables the SIGN BIT OUT pin.
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Comparator / DAC – connects the on-board comparator / the MSB of the DAC to the SIGN BIT OUT
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pin.
MSB / MSB/2 – Outputs MSB / MSB/2 of the DAC to the SIGN BIT OUT pin.
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