Button BAR of Main Window

UG-002

The buttons described in this section provide easy access to common features.

Load and Save

Clicking Load and Save allows you to load and save an AD9551 setup file. A setup file (.STP) is a text file that contains the AD9551 register setup file, plus any evaluation board settings.

Update

Clicking Update toggles the I/O update bit (Register 0x05, Bit 0) of the AD9551.

Reset

Clicking Reset resets the evaluation board and restores the AD9551 to its default power-up state. In addition, clicking Reset enables the VCO calibration function by writing the enable VCO calibration bit.

USING SOFTWARE TO CONTROL THE

FUNCTIONAL BLOCKS OF AD9551

The AD9551 evaluation software contains subsections that correspond to the major functional blocks of the AD9551. These subsections, most of which have their own window, are described in this section.

You can access each window by clicking Click for Details in the appropriate subsection box of the main window.

Most subsection boxes in the main window have a checkbox labeled SPI. If this box is selected, the software allows serial port writes when conditions are changed in the corresponding subsection window.

When a subsection window closes after clicking OK, you may notice that the LOAD button on the main window starts blinking. This indicates that there are settings that have not been loaded to the AD9551 evaluation board. Click LOAD to load these settings to the evaluation board.

Reference Input Boxes

The reference input boxes, which are labeled REF A (MHz) and REF B (MHz) in the main window, allow you to select an input frequency for REF A and REF B (see Figure 9 for an example for REF A). These boxes can be used to change the logic levels of the input frequency select pins.

Evaluation Board User Guide

009-08129 Figure 9. REF A List Box (in Main Window)

Reference Dividers

Clicking Click for Details in the REF A Divider and REF B Divider boxes of the main window accesses the RefA Input Divider window and the RefB Input Divider window (see Figure 10 for an example of the RefA Input Divider window).

These windows are used to set the desired reference divider for the integer or Σ-Δ modulator mode. The counters can be set individually.

08129-011

Figure 10. RefA Input Divider Window

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