3.2 Setting Up the EVM for ADC SPI Control3.3 Using the TI ADC SPI Interface Software
3.3.1 SPI Register Writes
3.3.2 SPI Register Write Using a Script File
3.3.2.1 ADS61xx Frequently Used Registers
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TI ADC SPI Control Interface
Users who wish to use the ADC SPI interface must supply 5 VDC to J20, which provides power to theUSB circuit. By default, the EVM comes with the ADC configured in parallel mode. In order to use the SPIinterface to control the ADC modes of operation, users must move several jumpers.
•Move jumper J3 to short positions 1–2, which places the ADC into serial operation mode.
•Move jumper J7 to short positions 1–2, which allows the USB circuit to control SCLK.
•Move jumper J6 to short positions 1–2, which allows the USB circuit to control SDATA.
•Move jumper J2 to short positions 1–2, which allows the USB circuit to control SEN.
Once the software is installed and the USB cable is connected, three primary modes of operating thesoftware are available: SPI Register Writes, SPI Register Write Using a Script File, andADS61xx/ADS61B23 Frequently Used Registers.
The most basic mode of operation allows full control of writing to individual register addresses. In the topleft corner of the interface screen (Figure 1 ), select the ADS61xx ADC from the ADC SPI Protocoldrop-down list. Next, type the Address Bytes(s) in hexadecimal (hex) and Data Byte(s) in hex, which canbe found in the device data sheet. When you are ready to send this command to the ADC, press "Enter"on your keyboard. The graph indicator is updated with the patterns sent to the ADC. The default inputs toboth the Address Byte(s) and Data Byte(s) fields are hex inputs as designated by the small xin thecontrol. Users can change the default input style by clicking on the "x" to binary, decimal, octal, or hex.Multiple register writes can be written simply by changing the contents of the Address Byte(s) and DataByte(s) field and pressing Enter again.
For situations where the same multiple registers must be written on a frequent basis, users can easily usea text editor to create a script file containing all ADC register writes. An example script file is located in the\\Install Directory\Script Files\ADS6145_LVDS_CourseGain.txt. Users who wish to take advantage ofwriting their own script files should start by using the ADS6145_LVDS_CourseGain.txt as a template file.When ready to write the contents of the script file to the ADC, users can press the Load Script button andthey will be prompted for the file location of their script file. The commands are sent to the ADC when theuser acknowledges the selection of the file.
For ease of use, several buttons have been added that allow one-click register writes of commonly usedfeatures found in Table 4 . These are found in the ADS61xx tab, as these commands are specific to theADS61xx ADC only. The software writes to the ADC both the contents of the associated address and datawhen the button is clicked. When the ADS61xx Reset button is pressed, it issues a software reset to theADC, and it resets the button values to match the contents inside of the ADC. The graph indicator plotsthe SPI commands written to the ADC when a button has been depressed.
SLAU206B – September 2007 – Revised April 2008 11Submit Documentation Feedback