Loading User Files -

You have the option of loading your own custom waveform files. You can access the user waveform load section by going to the Waveform window and typing 256 into the Waveform Code box.

Waveform Code

An User Defined Section will replace the Linear Chirp section.

User Defined Section

You can click on Open to bring up Open User Defined Waveform File window and select a custom user file. Note that your custom files should have an .uwf extension. Select your file and click on Open.

Open User Defined Waveform File Dialog Box

Once the file has been loaded the Data Length should have adjusted automatically. You just need to adjust the Memory Depth so that it is either equal to or larger than the Data Length. You do not need to click on the "Download" button. When you load the .uwf file the application automatically downloads the data to the DSM. To start the memory you simply need to click on the "Restart" button.

If you change your .uwf file in a text editor, you do not need to re-open the file. Simply click on "Reload" and the file will be updated in the application and automatically downloaded to the DSM.


Creating User Files

The user waveform files must have a .uwf extension and should be in ASCII encoding. You can create these with a typical text editor such as Notepad that is included with Windows. The file is basically a list of frequencies that you want to chirp separated by newlines. The frequencies are either specified in frequency word or absolute frequency. For absolute frequencies, the frequencies can be specified in either decimal or hexadecimal. The user waveform files must have two descriptors on the top of the file. An example of the descriptors is shown below:

        #type = 1
        #hex = 1
        

The #type specifies the type of frequency to be entered as well as if control bit words will be used. "1" is for frequency word without control bit words and "2" is for absolute frequency without control bit words. "5" is for frequency word with control bit words and "6" is for absolute frequency without control bit words. The four types are summarized in the table below. For frequency word, make sure that you do the right calculations and take the input clock frequency into consideration to get the desired output frequency. For absolute frequency, some of the frequencies might be rounded off to the nearest converted frequency word.

#type Description
1 Frequency words without control bit words
2 Absolute frequencies without control bit words
5 Frequency words with control bit words
6 Absolute frequencies with control bit words

The control bit words are basically two control bits that represent phase reset and marker. Bit 0 or the first LSB controls whether the marker is high or low while bit 1 or the second LSB controls the phase reset. For the phase reset bit, "0" turns phase reset off while "1" turns phase reset is on. For the marker bit, "0" turns marker low while "1" turns marker high. Here is a table showing the possible combinations of the control bit:

Dec / Hex Binary Phase Reset Marker
0 / 0x0 00 Off Low
1 / 0x1 01 Off High
2 / 0x2 10 On Low
3 / 0x3 11 On High

Phase Reset Marker Bits

If you have chosen to use the control bit words, you do not need to specify control bit word for every frequency data point. The default setting if you do not set a frequency control word is "0" meaning no phase reset and marker low. So you only need to specify the data points where you do want phase reset or marker.

The #hex specifies if the absolute frequency will be specified in decimal or hexidecimal. "0" is for decimal and "1" is for hexadecimal. Note that if you choose the type to be frequency word then you can ONLY use hexadecimal.

Please note that the control bit words format is also controlled by the #hex setting. If #hex is set to decimal then the control bit words should also be in decimal and if #hex is set to hexadecimal then the control bit words should also be in hexadecimal.


Example User Files

» Frequency Word Demo Chirp

This file is a replication of the Demo waveform that is displayed everytime the DSM is turned on. It is expressed in hexadecimal frequency word as described in the top two lines.


» Decimal Linear Chirp

This file does linear chirping by specifying the absolute frequencies in decimal. When the decimal frequencies are fed into the software, they will be rounded to the closest frequency word.


» Non-Linear Frequency Word Chirp

This file uses frequency words in hexadecimal. This waveform shows non-linear chirping with uneven spacing between every other frequency.


» Exponential Frequency Word Chirp

This file also uses frequency words in hexadecimal. This waveform demonstrates exponential chirping doubling the frequency every time.


» Non-Linear Frequency Word Chirp with Control Bit Words

This file also uses frequency words in hexadecimal but this time uses the control bit words to control phase reset and markers.