• AD9834

• EVAL-AD9834SDZ

This lab presents the steps to setup an environment for using the EVAL-AD9834SDZ evaluation board together with the BeMicro SDK USB stick, the Nios II Embedded Development Suite (EDS) and the Micrium μC-Probe run-time monitoring tool. Below is presented a picture of the EVAL-AD9834SDZ Evaluation Board with the BeMicro SDK Platform.

Below is presented a picture of SDP-B Controller Board with the EVAL-AD9834SDZ Evaluation Board.

The AD9834 is a 75 MHz, low power DDS device capable of producing high performance sine and triangular outputs. It also has an on-board comparator that allows a square wave to be produced for clock generation. Consuming only 20 mW of power at 3 V makes the AD9834 an ideal candidate for power-sensitive applications.

The EVAL-AD9834SDZ evaluation board is designed to help customers quickly prototype new AD9834 circuits and reduce design time. A high performance, on-board 75 MHz trimmed general oscillator is available to use as the master clock for the AD9834 system. Various links and SMB connectors are also available on the EVAL-AD9834SDZ board to maximize the usability.

• AD9834 Product Info - pricing, samples, datasheet
• EVAL-AD9834SDZ evaluation board user guide
• BeMicro SDK
• Nios II Embedded Development Suite (EDS)
• Micrium uC-Probe

The first objective is to ensure that you have all of the items needed and to install the software tools so that you are ready to create and run the evaluation project.

Below is presented the list of required hardware items:

• Arrow Electronics BeMicro SDK FPGA-based MCU Evaluation Board
• BeMicro SDK/SDP Interposer adapter board
• EVAL-AD9834SDZ evaluation board
• Intel Pentium III or compatible Windows PC, running at 866MHz or faster, with a minimum of 512MB of system memory

Below is presented the list of required software tools:

• Quartus II Web Edition design software v11.0
• Nios II EDS v11.0
• uC-Probe run-time monitoring tool, version 2.5

The Quartus II design software and the Nios II EDS is available via the Altera Complete Design Suite DVD or by downloading from the web.

The Micrium uC/Probe Trial version 2.5 is available via download from the web at http://micrium.com/tools/ucprobe/trial/. After installation add to the “Path” system variable the entry “%QUARTUS_ROOTDIR%/bin/“ on the third position in the list.

• Lab Design Files

Create a folder called “ADIEvalBoardLab” on your PC and extract the ad9834_evalboardlab.zip archive to this folder. Make sure that there are NO SPACES in the directory path. After extracting the archive the following folders should be present in the ADIEvalBoardLab folder: FPGA, Software, ucProbeInterface, NiosCpu.

A notable challenge in embedded systems development is to overcome the lack of feedback that such systems typically provide. Many developers resort to blinking LEDs or instrumenting their code with printf() in order to determine whether or not their systems are running as expected. Micrium provides a unique tool named μC-Probe to assist these developers. With this tool, developers can effortlessly read and write the variables on a running embedded system. This section presents the steps required to install the Micrium uC-Probe software tool and to run the demonstration project for the ADI evaluation board. A description of the uC-Probe demonstration interface is provided.

Launch uC-Probe from the Start → All Programs → Micrium → uC-Probe.

Select uC-Probe options.

• Click on the uC-Probe icon on the top left portion of the screen.
• Click on the Options button to open the dialog box.

Set target board communication protocol as JTAG UART

• Click on the Communication tab icon on the top left portion of the dialog box
• Select the JTAG UART option.

Setup JTAG UART communication settings

• Select the JTAG-UART option from the Communication tab.
• Press the Open File button to select the JTAG Debug Information file (.jdi)
• Navigate to the ADIEvalBoardLab/FPGA folder and select the BeMicroSDK.jdi file. Press Open.
• Type the value 1 in the the Device Id window.

• Select uCProbe_uart(0) from the Instance Id pulldown menu.

• Press Apply and OK to exit the options menu. The embedded target has two UARTs. uC-Probe will be communicating with the uCProbe_uart.

• Click the Open option from the uC-Probe menu and select the file ADIEvalBoardLab/ucProbeInterface/AD9834_Interface.wsp.

• Before opening the interface uC-Probe will ask for a symbols file that must be associated with the interface. If the lab was done according to the steps provided in the Quick Evaluation section, select the file ADIEvalBoardLab/ucProbeInterface/ADIEvalBoard.elf to be loaded as a symbol file, otherwise select the file ADIEvalBoardLab/FPGA/software/ADIEvalBoard/ADIEvalBoard.elf to be loaded as a symbol file.

• Run the demonstration project by pressing the Play button.

The following figure presents the uC-Probe interface that can be used for monitoring and controlling the operation of the EVAL-AD9834SDZ evaluation board.

Section A is used to activate the board and monitor activity. The communication with the board is activated / deactivated by toggling the ON/OFF switch. The Activity LED turns green when the communication is active. If the ON/OFF switch is set to ON and the Activity LED is BLACK it means that there is a communication problem with the board. See the Troubleshooting section for indications on how to fix the communication problems.

Section B is used to set or clear the bits and pins which affect the signal from the IOUT output.

Programming Method:

• HW – selects the control pins to implement the register selection, reset, and DAC power-down functions.
• SW – selects the control bits to implement the register selection, reset, and DAC power-down functions.

Frequency control:

• F1 – FREQ1 register is used in the phase accumulator.
• F0 – FREQ0 register is used in the phase accumulator.

Phase control:

• P1 – PHASE1 register data is added to the output of the phase accumulator.
• P0 – PHASE0 register data is added to the output of the phase accumulator.

IOUT Output:

• Ramp – Triangle signal at the output.
• Sin – Sinusoidal signal at the output.

HW Pins:

• F1 / F0 – This pin controls which frequency register, FREQ0 or FREQ1, is used in the phase accumulator.
• P1 / P0 – This pin controls which phase register, PHASE0 or PHASE1, is added to the phase 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;
• put the dial to position 1 and move the slider to 3;
• put the dial to position 2 and move the slider to 2;
• put the dial to position 3 and move the slider to 1.

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.
• Comparator / DAC – connects the on-board comparator / the MSB of the DAC to the SIGN BIT OUT pin.
• MSB / MSB/2 – Outputs MSB / MSB/2 of the DAC to the SIGN BIT OUT pin.

Section E is used to select the sleep mode of the circuit.

Section F is used to activate and control the Frequency Sweep function.

Sweep ON / Sweep OFF: Turn ON / OFF the sweep function.

Start / Stop: Start / Stop the sweep function.

Start Frequency: Value of the start frequency.

Stop Frequency: Value of the stop frequency.

Step Frequency: Value of the increment size.

Delay: Value of the delay between each frequency increment.