DdsModTerm software for AD9850/51 modules

🔘In the post 📮dated 📅27 July 2023, about how a µ-controller and a smart phone🖁 App could be used to upload 🠝 configuration settings to  modules based on AD9850 and AD9851 DDS chips in order to generate a frequency, it was briefly mentioned that  a USB dongle and pc interface software was another method in use here. As that software has recently been updated it would now be a good time to give a description of that method also.

The SpacerLabs dedicated pc 💻software called "DdsModTerm" is the user interface and was first released in about 2015. Since then there have been 15 revisions; the latest appearing this month.

'DdsModTerm' user interface

The clock 🕰frequency and the required output frequency and phase are entered, either manually or by recall from memory. By clicking 'Confirm', the software generates the 5 configuration bytes required from the user input data. In the example in the image above the output frequency is 137700Hz & bytes hexadecimal 00C88AC604. The pc 💻is connected to the serial data interface of the DDS module board via a COM port and the SpacerLabs USB-SPI dongle. Clicking 'Update DDS' then uploads the bytes using  SPI protocol to the registers of the DDS chip and the programmed frequency  ∿  is then present on the output. 

(L) USB-SPI dongle (R) AD9851 DDS chip evaluation board on adaptor

Other features of the software include up/down step 🪜tuning, slider tuning control, eeprom view, 3 memories for storing frequency, saving custom clock🕓, alias frequencies calculated, and general purpose output ( GPO ) toggling on/off.

The dongle and software are available from us. Post a comment, contact us by email or use the form below to receive more information. Note that both AD9850 & AD9851 DDS devices are supported.🔘

( Click on images to enlarge detail. )

SPI = Serial Peripheral Interface, 3-wire bus.

AD9850, AD9851 : 🔗Analog Devices Inc. parts, 32-bit CMOS Direct Digital Synthesiser (DDS) chips.