This document presents the steps to setup an environment for using the EVAL-AD5781SDZ evaluation board together with the Xilinx KC705 FPGA board, the Xilinx Embedded Development Kit (EDK) and the Micrium µC-Probe run-time monitoring tool. Below is presented a picture of the EVAL-AD5781SDZ Evaluation Board with the Xilinx KC705 board.
For component evaluation and performance purposes, as opposed to quick prototyping, the user is directed to use the part evaluation setup. This consists of:
The SDP-B controller board is part of Analog Devices System Demonstration Platform (SDP). It provides a high speed USB 2.0 connection from the PC to the component evaluation board. The PC runs the evaluation software. Each evaluation board, which is an SDP compatible daughter board, includes the necessary installation file required for performance testing.
Note: it is expected that the analog performance on the two platforms may differ.
Below is presented a picture of SDP-B Controller Board with the EVAL-AD5781SDZ Evaluation Board.
The EVAL-AD5781SDZ is a full-featured evaluation board, designed to allow the user to easily evaluate all features of the AD5781 voltage output, 18-bit DAC. The AD5781 pins are accessible at on-board connectors for external connection. The board can be controlled by two means, via the on-board connector (J6) or via the system development platform connector (J3).
The AD5781 is a high precision, 18-bit digital-to-analog converter (DAC), designed to meet the requirements of precision control applications. The output range of the AD5781 is configured by two reference voltage inputs. The device is specified to operate with a dual power supply of up to 33 V.
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.
The following table presents a short description the reference design archive contents.
|Bit||Contains the KC705 configuration file that can be used to program the system for quick evaluation.|
|Microblaze||Contains the EDK project for the Microblaze softcore that will be implemented in the KC705 FPGA.|
|Software||Contains the source files of the software project that will be run by the Microblaze processor.|
|uCProbeInterface||Contains the uCProbe interface and the .elf symbols file used by uC-Probe to access data from the Microblaze memory.|
Before connecting the ADI evaluation board to the Xilinx KC705 make sure that the VADJ_FPGA voltage of the KC705 is set to 3.3V. For more details on how to change the setting for VADJ_FPGA visit the Xilinx KC705 product page.
At this point everything is set up and it is possible to start the evaluation of the ADI hardware through the controls in the uC-Probe application provided in the reference design.
Launch uC-Probe from the Start → All Programs → Micrium → uC-Probe.
Select uC-Probe options.
Set target board communication protocol as RS-232
Setup RS-232 communication settings
The following figure presents the uC-Probe interface that can be used for monitoring and controlling the operation of the EVAL-AD5781SDZ evaluation board.
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.
The value of the AD5781 DAC Register is changed using the slider located under the DAC Register Value (18-bit) label. The selected value is displayed in the red numeric box located next to the slider.
The value of the AD5781 Clearcode Register is changed using the slider located under the Clearcode Register Value (18-bit) label. The selected value is displayed in the red numeric box located next to the slider.
The sliders Vref+ and Vref- are used to specify the reference voltages set on the evaluation board.
The DAC’s output voltage is displayed in the numeric box having the label Output voltage.
The values of the Control Register’s bits are indicated by the LEDs situated to the right of the Control Register label. When a LED id lit it means that the corresponding bit’s value is 1.
The values of the Status Control Register’s bits are indicated by the LEDs situated to the right of the Status Control Register label. When a LED id lit it means that the corresponding bit’s value is 1.
The DAC register coding is controlled by the DAC Register Coding switch. When the switch is set to the B0 position the binary offset coding is selected by setting the BIN/2sC bit of the Control Register to 1. When the switch is set to the C2 position the two’s complement coding is selected by setting the BIN/2sC bit of the Control Register to 0.
The Load DAC switch is used to control the LDAC signal of the AD5781. When the switch is pressed the DAC register (and consequently the DAC’s output) is updated with the contents of the DAC’s input register.
The RBUF Control switch is used to set the value of the RBUF bit from the Control Register. When the switch is active the bit’s value is set to 1.
In case there is a communication problem with the board the follwing actions can be perfomed in order to try to fix the issues: