BF70x SPORT with External clock


does BF70x's SPORT need three external clocks after enabling to initialize?

Background: the BF512 needs that - see ADSP BF51x hardware reference Revision 1.2 from February 2013, first paragraph on page 19-30.

Reason: I need to connect an AD7665 on a SPORT, that means external clock and external frame sync; the problem is that AD7665's frame sync is active for the entire clock period, which may cause data scrambling because the ADC's conversion signal is asynchronously generated.

For the BF512 I solved this issue by generating RFS with a GPIO while monitoring ADC's frame signal in software.

Thank you!

  • 0
    •  Analog Employees 
    on Aug 26, 2015 11:47 AM

    Hi Petrov,

      In the external clock and external frame sync mode, SPORT of BF70x needs additional clocks after enabling for initialization.

    It needs  additional 7 SPORT clocks( both in Normal and Gated clock) mode when CLK and FS are external.You can refer to page 26-40 of SPORT chapter of HRM for more details. Even though this information is mentioned in Gated clock mode, same is applicable for normal mode.