Although the EVM GUI does not allow direct access to the levels and timing configuration of the ADC digital interface, the EVM GUI does give users high-level control over virtually all functions of the ADS9110 including interface modes, sampling rate, and number of samples to be captured.

Figure 6-2 identifies the input parameters of the GUI (as well as the default values) through which the various functions of the ADS9110 can be exercised. These settings are global because the settings persist across the GUI tools listed in the top left pane (or from one page to another).

Figure 6-2 EVM GUI Global Input Parameters

The host configuration options in this pane allow the user to choose from various SPI and multiSPI host interface options available on the ADS9110. The host always communicates with the ADS9110 using the standard SPI protocol over the single SDI lane, irrespective of the mode selected for data capture.

The drop-down boxes under the Interface Configuration sub-menu allow the user to select the data capture protocol. The SDO Width drop-down allows selection between Single-, Dual- and Quad-SDO lanes. The SDO Mode drop-down allows selection between Standard SPI and multiSPI modes.

In SPI mode, the SDI Mode drop-down allows selection between the four SPI protocol combinations for CPOL and CPHA.

In multiSPI mode, the Clock Source drop-down menu allows selection between Source and System Synchronous modes; the Data Rate drop-down menu allows selection between SDR and DDR modes. Detailed descriptions of each of these modes is available in the ADS9110 18-Bit, 2MSPS, 15mW, SAR ADC With Enhanced Performance Features data sheet). The selected data capture protocol is summarized in the Protocol Selected indicator box.

The user can select SCLK Frequency and Sampling Rate on this paneand is dependent of the protocol selected. The GUI allows the user to enter the targeted values for these two parameters and the GUI computes the best values that can be achieved, considering the timing constraints of the selected device protocol.

The user can specify a target SCLK frequency (in Hz) and the GUI tries to match this frequency as closely as possible by changing the PHI PLL settings and the achievable frequency can differ from the target value entered. Similarly, the sampling rate of the ADC can be adjusted by modifying the Target Sampling Rate argument (also in Hz). The achievable ADC sampling rate can differ from the target value, depending on the applied SCLK frequencyand selected Device Mode and the closest match achievable is displayed. This pane, therefore, allows the user to try various settings available on the ADS9110 in an iterative fashion until the user converges to the best settings for the corresponding test scenario.

The final option in this pane is the selection for the Update Mode. The default value is Immediate, indicating that the interface settings selection made by the user is applied to configure both the host and the ADS9110 instantly. Manual indicates that the selection made is made only when the user finalizes the choices and is ready to configure the device.

The Device Reset button functions as a Master RESET to both the ADS9110EVM and the GUI. When the button is pressed, the ADC RESETs to the RESET configuration explained in the ADS9110 18-Bit, 2MSPS, 15mW, SAR ADC With Enhanced Performance Features data sheet). The GUI also updates the Interface Configuration settings and the Register Map to reflect the device RESET state.