SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
DPLL_ABE supports fractional synthesis, that is, the frequency multiplication factor M can be programmed as fractional. The fractional part of M-factor is programmed in the 18-bit CTRL_CORE_SMA_SW_2[17:0] ABE_DPLL_REGMF_CONTROL register. Similarly to REGM, REGMF value is loaded into DPLL at the rising edge of TENABLE signal. Fractional synthesis is typically associated with additional jitter overhead. Refer to the device-specific Data Manual for DPLL jitter characteristics.
The allowed range of M for fractional synthesis to operate is M = 20 and M = 2042.
The integer-only division takes place when ABE_DPLL_REGMF_CONTROL is programmed to 0x0.