The DPLL_SATA factors must be calculated based on the required input and output frequencies, keeping the PLL internal reference frequency (REFCLK) in the appropriate range (0.62 to 2.5 MHz).
- The REGM factor is programmed in the DPLLCTRL_SATA.PLL_CONFIGURATION1[20:9] PLL_REGM bit field.
- The fractional part of REGM factor is programmed in the DPLLCTRL_SATA.PLL_CONFIGURATION4[17:0] PLL_REGM_F bit field.
- The REGN factor is programmed in the DPLLCTRL_SATA.PLL_CONFIGURATION1[8:1] PLL_REGN bit field.
- The DCO frequency range is set in the DPLLCTRL_SATA.PLL_CONFIGURATION2[3:1] PLL_SELFREQDCO bit field.
- PLL_SELFREQDCO should be set to 0x2, if 750 MHz < CLKDCOLDO [MHz] < 1500 MHz
- PLL_SELFREQDCO should be set to 0x4, if 1250 MHz < CLKDCOLDO [MHz] < 2500 MHz
- The SD divider is programmed in the DPLLCTRL_SATA.PLL_CONFIGURATION3[17:10] PLL_SD bit field. The DPLLCTRL_SATA.PLL_CONFIGURATION2[3:1] PLL_SELFREQDCO bit field should be programmed depending on the value of CLKDCOLDO = CLKINP × M/(N + 1). The formulas are shown in Figure 26-7.
Figure 26-7 shows the programming sequence.
Note: - The equation for SATA_PHY_TX/SATA_PHY_RX (MHz) applies to the CLKDCOLDO of the DPLL_SATA.
- For normal operation CLKDCOLDO output frequency of the DPLL_SATA should be either 750 MHz (SATA-1 mode) or 1500 MHz (SATA-2 mode).
Table 26-5 summarizes the registers for the DPLLCTRL_SATA programming sequence.
Table 26-5 Register Call Summary for SATA PLL Programming Sequence