SBAS495D June 2010 – August 2021 PCM9211
PRODUCTION DATA
The PCM9211 an has on-chip PLL (including a voltage-controlled oscillator, or VCO) for recovering the clock from the S/PDIF input signal.
The VCO-derived clock is identified as the PLL clock source.
When locked, the onboard PLL generates a system clock that synchronizes with the input biphase signal. When unlocked, the PLL generates its own free-run clock (from the VCO).
The generated system clocks from the PLL can be set to fixed multiples of the input S/PDIF frequency. Register 30h/PSCK[2:0] can configure the output clock to 128fS, 256fS or 512fS.
The PCM9211 also has an automatic default output rate that is calculated based on the incoming S/PDIF frequency. This calculation and rate are controlled by Register 30h/PSCKAUTO. In its default mode, the SCK dividing ratio is configured according to these parameters:
PSCKAUTO takes priority over any settings in PSCK[2:0]. PSCK[2:0] only becomes relevant in the system when the PSCKAUTO Register is set to 0.
The PCM9211 can decode S/PDIF input signals between sampling frequencies of 7 kHz and 216 kHz for all PSCK[2:0] settings. The relationship between the output clock (SCKO, BCKO, LRCKO) at the PLL source and PSCK[2:0] selection is shown in Table 7-4.
OUTPUT CLOCK AT PLL SOURCE | PSCK[2:0] SETTING | ||||
---|---|---|---|---|---|
SCKO | BCKO | LRCKO | PSCK2 | PSCK1 | PSCK0 |
128fS | 64fS | fS | 0 | 0 | 0 |
256fS | 64fS | fS | 0 | 1 | 0 |
512fS(1) | 64fS | fS | 1 | 0 | 0 |
In PLL mode, the output clocks (SCKO, BCKO, LRCKO) are generated from the PLL source clock.
The relationship between the sampling frequencies (fS) of the input S/PDIF signal and the frequency of LRCKO, BCKO, and SCKO are shown in Table 7-5.
LRCK | BCK | SCK(1) | ||
---|---|---|---|---|
fS | 64fS | 128fS | 256fS | 512fS |
8 kHz | 0.512 MHz | 1.024MHz | 2.048 MHz | 4.096 MHz |
11.025 kHz | 0.7056 MHz | 1.4112 MHz | 2.8224 MHz | 5.6448 MHz |
12 kHz | 0.768 MHz | 1.536 MHz | 3.072 MHz | 6.144 MHz |
16 kHz | 1.024 MHz | 2.048 MHz | 4.096 MHz | 8.192 MHz |
22.05 kHz | 1.4112 MHz | 2.8224 MHz | 5.6448 MHz | 11.2896 MHz |
24 kHz | 1.536 MHz | 3.072 MHz | 6.144 MHz | 12.288 MHz |
32 kHz | 2.048 MHz | 4.096 MHz | 8.192 MHz | 16.384 MHz |
44.1 kHz | 2.8224 MHz | 5.6448 MHz | 11.2896 MHz | 22.5792 MHz |
48 kHz | 3.072 MHz | 6.144 MHz | 12.288 MHz | 24.576 MHz |
64 kHz | 4.096 MHz | 8.192 MHz | 16.384 MHz | 32.768 MHz |
88.2 kHz | 5.6448 MHz | 11.2896 MHz | 22.5792 MHz | 45.1584 MHz |
96 kHz | 6.144 MHz | 12.288 MHz | 24.576 MHz | 49.152 MHz |
128 kHz | 8.192 MHz | 16.384 MHz | 32.768 MHz | N/A |
176.4 kHz | 11.2896 MHz | 22.5792 MHz | 45.1584 MHz | N/A |
192 kHz | 12.288 MHz | 24.576 MHz | 49.152 MHz | N/A |