ZHCSIM2D June 2010 – August 2021 PCM9211
PRODUCTION DATA
The second sampling frequency calculator can be used to calculate the sampling frequency of DIR, ADC, AUXIN0, AUXIN1, AUXIN2, Main Output Port, AUX Output Port, and DIT Input. Figure 7-19 illustrates the sampling frequency calculator sources.
The calculated sampling frequency fS is decoded to 4-bit data and stored in the PFSOUT[3:0] register. The input source of this counter is selectable from AUXIN0, AUXIN1, AUXIN2, DIR, ADC, Main Output Port, AUX Output Port, and DIT by using the Register 37h/PFSTGT[3:0].
To use this function, a 24.576-MHz clock source must be supplied to the XTI pin. The 24.576-MHz clock is used as a reference clock. If the XTI pin is connected to DGND, the calculation is not performed. If there is an error in the XTI clock frequency, the calculation result and range will be incorrect.
Register 38h/PFSST indicates the calculator status. It is recommended that PFSST is checked (for complete status) before reading PFSOUT[3:0].