Use of 15 MHz reference Oscillator with LMX2502. Code Loader 4.0 allows use of 15 MHz oscillator but dividers are set up for a 19.20 or 19.68 MHz reference. LMX2502 datasheet says to contact TI for use of other reference frequencies. OSC_FREQ bit needs to be set but only two values possible(0 for 19.20 MHz and 1 for 19.68 MHz). Desired output frequency range of LMX2502 is 1610 to 1617 MHz. Again TI datasheet says to contact TI for use of other frequencies (LMX2502 spec range for RF VCO is 1619.62 to 1649.62)