To use SYSREF, do the these steps:
- Put the device in SYNC mode using the procedure already outlined.
- Figure out IncludedDivide the same way it is done for SYNC mode.
- Calculate the SYSREF_DIV_PRE value such that the interpolator frequency (fINTERPOLATOR) is in the range of 800 to 1500 MHz. fINTERPOLATOR = fVCO / IncludedDivide / SYSREF_DIV_PRE. Make this frequency a multiple of fOSC if possible.
- If using master mode (SYSREF_REPEAT = 0), ensure SYSREFREQ pin is high.
- If using repeater mode (SYSREF_REPEAT = 1), set up the pulse count if desired. Pulses are created by toggling the SYSREFREQ pin.
- Adjust the delay between the RFOUTA and RFOUTB signal using the JESD_DACx_CTRL fields.