• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 1581 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

RTOS/AWR1642BOOST: Why does an example profileCfg CLI command contradict the mmWave Link doxygen?

Samuel Miller99
Expert 1005 points
Part Number: AWR1642BOOST
Other Parts Discussed in Thread: AWR1642

Tool/software: TI-RTOS

In the mmWave Link doxygen, the start frequency parameter is specified as follows:

rlUInt32_t  startFreqConst
  Start frequency for each profile 
1 LSB = 3.6e9 / 2^26 Hz = 53.644 Hz 
Valid range: 0x5471C71B to 0x5A000000 

Where 0x5471C71B = 1.4167e9 and 0x5A000000 = 1.5099e9. Multiply both of those numbers by the LSB, 53.644Hz, and get values that are essentialls 76e9 and 81e9 which makes sense because it is the operating bandwidth of the AWR1642. 

My question is, why is the default value for this field in the profileCfg 77? This is from the capture demo in SDK 1.1:

profileCfg 0 77 20 5 80 0 0  40 1 256 6000 0 0 30

I have used this configuration and managed to get ADC data that made intuitive sense.

Should I change this value instead to 77e9/53.644 = 1.4354e+09 so

profileCfg 0 1435400000 20 5 80 0 0 40 1 256 6000 0 0 30

Would this work?

  • 0
    TI__Mastermind 24955 points

    Samuel,

    Please refer to the SDK User's Guide for questions related to the configuration files (.cfg) that are sent to the device over UART. In the configuration file, the valid values for the profileCfg CLI command are 76 to 81, which correspond to the minimum and maximum values in GHz that the AWR1642 can transmit. Once this command is parsed by the device, the device firmware will translate it into the corresponding hex code that you can see in the doxygen. This was done to make the configuration files easier to read.

    Please also keep in mind that the AWR1642 implements two VCOs (voltage controlled oscillators) that cover difference frequency bands. VCO1 covers the 76-77 GHz band while VCO2 covers the 77-81 GHz band. This particular profile was chosen to start at 77 GHz to take advantage of the larger bandwidth.


    Regards,
    Kyle

  • 0 in reply to Kyle Cousino
    Expert 1005 points

    Thanks Kyle. I keep forgetting that I have to reference the newest SDK for the updates on the .cfg commands. I've been using SDK 1.1 in order to run the capture demo and save cached ADC data via CCS, so I keep looking at the SDK v1.1. Anyone who has this problem in future threads be aware of the difference (SDK v1.1 shown in screenshot). SDK 2.0 is more descriptive, saying "any value as per mmwavelink doxygen but in GHz".

  • 0 in reply to Samuel Miller99
    Expert 1005 points
    Another follow-up to this though, so if it specifies "values in GHz" those values have to be whole numbers? Can I start at 77.5 GHz if I really want to?
  • 0 in reply to Samuel Miller99
    TI__Mastermind 24955 points
    Samuel,

    As stated in the user's guide, the start frequency value is a float value. So you can start at 77.5 GHz if you wanted to. You could also start at 78.41 GHz if you wanted to. The choice is yours.

    Regards,
    Kyle