JAJSEY1C April 2019 – March 2022 ADC12DJ5200RF
In basic NCO frequency-setting mode (NCO_RDIV = 0x0000), the NCO frequency setting is set by the 32-bit register value, FREQAx and FREQBx (x = 0 to 3). The NCO frequency for DDC A can be calculated using Equation 5, where FREQAx can be replaced by FREQBx to calculate the NCO frequency for DDC B. FREQAx and FREQBx can be considered either a 2's complement number (–2147483648 to 2147483647) or as an offset binary number (0 to 4294967295).
Changing the FREQAx and FREQBx register settings during operation results in a non-deterministic NCO phase. If deterministic phase is required, the NCOs must be resynchronized; see the NCO Phase Synchronization section.