SLAS763C August 2012 – October 2018 PCM5121 , PCM5122
PRODUCTION DATA.
Recommended values for the PLL can be found after the register descriptions in this data sheet. Different values are defined based on the device configuration for VREF or VCOM mode.
Other configurations are possible, at your own risk.
Below are details of the register locations, as well as the nomenclature for the table of registers found at the end of this document.
DIVIDER | FUNCTION | BITS |
---|---|---|
PLLE | PLL enable | Page 0, Register 4, D(0) |
PPDV | PLL P | Page 0, Register 20, D(3:0) |
PJDV | PLL J | Page 0, Register 21, D(5:0) |
PDDV | PLL D | Page 0, Register 22, D(5:0) |
Page 0, Register 23, D(7:0) | ||
PRDV | PLL R | Page 0, Register 24, D(3:0) |
COLUMN | DESCRIPTION |
---|---|
fS (kHz) | Sampling frequency |
RSCK | Ratio between sampling frequency and SCK frequency (SCK frequency = RSCK × sampling frequency) |
SCK (MHz) | System master clock frequency at SCK input (pin 20) |
PLL VCO (MHz) | PLL VCO frequency as PLLCK in Figure 63 |
P | One of the PLL coefficients in Equation 3 |
PLL REF (MHz) | Internal reference clock frequency which is produced by SCK / P |
M = K * R | The final PLL multiplication factor computed from K and R as described in Equation 3 |
K = J.D | One of the PLL coefficients in Equation 3 |
R | One of the PLL coefficients in Equation 3 |
PLL fS | Ratio between fS and PLL VCO frequency (PLL VCO / fS) |
DSP fS | Ratio between audio processor operating clock rate and fS (PLL fS / NMAC) |
NMAC | The audio processor clock divider value in Table 34 |
DSP CLK (MHz) | The audio processor operating frequency as DSPCK in Figure 63 |
MOD fS | Ratio between DAC operating clock frequency and fS (PLL fS / NDAC) |
MOD f (kHz) | DAC operating frequency as DACCK in Figure 63 |
NDAC | DAC clock divider value in Table 34 |
DOSR | OSR clock divider value in Table 34 for generating OSRCK in Figure 63. DOSR must be chosen so that MOD fS / DOSR = 16 for correct operation. |
NCP | NCP (negative charge pump) clock divider value in Table 34 |
CP f | Negative charge pump clock frequency (fS × MOD fS / NCP) |
% Error | Percentage of error between PLL VCO / PLL fS and fS (mismatch error).
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