• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 3 answers
  • Subscribers 31 subscribers
  • Views 728 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

IWR1642: Availability of SYNC_OUT

Andrew Chadwick
Prodigy 120 points
Part Number: IWR1642
Other Parts Discussed in Thread: , AWR1243

Hi,

I want to use the SYNC_OUT signal from the IWR1642 as a timing reference for another (unrelated) device. But it doesn't appear to be present when testing with my IWR1642BOOST (probing at e.g. the pads for R108).

My EVM has an ES1.0 device and I'm running the Traffic Monitoring demo v2.0 from the MMWave Industrial Toolbox v2.3. Frames are software triggered, and output as expected.

I can't see anything in the formal part documentation to suggest that SYNC_OUT isn't available on the IWR1642, but some other forum posts disagree: e.g. the first thread below indicates that it is available, the second states that it isn't! Please could someone clarify? If it is available, how do I enable it?

https://e2e.ti.com/support/sensors/f/1023/t/670963

https://e2e.ti.com/support/sensors/f/1023/p/639919/2360401

Thanks,

Andy

  • 0
    TI__Mastermind 33805 points
    Hi Andy,

    There is a FMCW_SYNCOUT, which is the signal sourced from the 20Ghz synth is different from the SYNC_OUT which is to trigger the frame start.
    To use the SYNC_OUT , SYNC_IN feature you need to activate it in the SW as it is not enabled by default

    Regards,
    Charles O
  • 0 in reply to Charles Oladimeji
    Prodigy 120 points

    Hi Charles,

    Thanks for the reply. I'm aware of the difference between SYNC_OUT and FMCW_SYNCOUT on the AWR1243. I'm only concerned with SYNC_OUT on the IWR1642.

    How do I enable SYNC_OUT in the software? I can't find any reference to this in any of the documentation, or source code.

    Andy

  • 0 in reply to Andrew Chadwick
    TI__Mastermind 25795 points

    Hello,

       Typically SYNC_OUT signal is used as synchronization for the Cascade configuration to synchronize the slave device in AWR1243 context.

    In IWR1642 this use case is not supported as cascading feature is not present in this device.  Hence default boot loader and application running in the MCU will not enable this signal by default.

    However if you would like to enable this pin you may have write the Pin-mux register shown below in the datasheet. 

    Thanks and regards,

    CHETHAN KUMAR Y.B.

  • 0 in reply to CHETHAN KUMAR Y.B.
    Prodigy 120 points
    Hi Chethan,

    I've tried setting the PINMUX as follows:

    Pinmux_Set_OverrideCtrl(SOC_XWR16XX_PING13_PADBC, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL);
    Pinmux_Set_FuncSel(SOC_XWR16XX_PING13_PADBC, SOC_XWR16XX_PING13_PADBC_SYNC_OUT);

    I've also tried replacing PINMUX_OUTEN_RETAIN_HW_CTRL in the above with PINMUX_OUTPUT_EN to force this pin to be enabled; and configuring the SYNC_OUT signal on the GPIO_2 pin (K13) instead.

    None of this helps, I still don't see the SYNC_OUT signal on my EVM.

    Is there something else I need to configure?

    Thanks,
    Andy
  • 0 in reply to Andrew Chadwick
    TI__Mastermind 25795 points

    Hello,

       For the SYNC_OUT signal is defined for the Cascade application.

    In cascade configuration Multi-chip master would provide the SYNC_signal to the slaves.

    Multichip_slave will receive the sync_out from master to sync_in of slave device. For the Sync_out signal muti-chip master API need to be issued. 

     

    Also If you are using TI EVM you need to install resistor R108 on the EVM to bring the SYNC_OUT pin on J6 connector. 

    For sending the Trigger signal, You could define SYNC_OUT signal or any GPIO signal as any GPO  (OUTPUT BUFFER) and could send a "Pulse" on the I/O buffer. 

    For this you need to ensure  right pin is selected and right pin muxing configuration is used. 

    Thanks and regards,

    CHETHAN KUMAR Y.B.

  • 0 in reply to CHETHAN KUMAR Y.B.
    Prodigy 120 points

    OK, so I've tried enabling cascading by setting the 3rd parameter of the channel config message, i.e., channelCfg 15 1 1 rather than channelCfg 15 1 0.

    The config still works (no errors) but I still don't see any SYNC_OUT strobe at either the R108 pads, or at the device side of the SOP1 jumper.

    So I think I have to conclude that - despite its inclusion on the IWR1642 datasheet - the SYNC_OUT signal is permanently disabled for the IWR1642 in the device firmware.

    I have a workaround whereby the DSS frame start interrupt handler sends a message to the MSS, and the MSS asserts a GPIO output - this works OK and I assume the latency with respect to the true frame start is small. I guess an alternative would be to define a new frame start interrupt handler on the MSS but I haven't tried this. Any comments on these approaches would be appreciated, otherwise I'll close the thread.

    Thanks,

    Andy

  • 0 in reply to Andrew Chadwick
    TI__Mastermind 25795 points
    Hello,

    Yes, that is a very nice idea, latency with respect to the true frame start would be small.
    I guess trigger signal that you plan to use is not another Radar chip for cascading application.
    As cascading application would require much tighter timing control.

    Thanks and regards,
    CHETHAN KUMAR Y.B.