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6.10 GPIO Tab
Kit Operation
This frequency will then be used to calculate the actual Fsref frequency, and the ADC and DAC sample
rates, after the NADC and NDAC factors are applied to the Fsref. If dual rate mode is desired, this option
can be enabled for either the ADC or DAC by pressing the corresponding Dual Rate Mode button.
6.9.2 Use With The PLL
When PLLDIV_OUT is selected as the codec clock source, the PLL will be used. The PLL clock source is
chosen using the PLLCLK_IN control, and may be set to either MCLK or BCLK. The PLLCLK_IN
frequency is then entered into the PLLCLK_IN Source box.
The PLL_OUT and PLLDIV_OUT indicators show the resulting PLL output frequencies with the values set
for the P, K, and R parameters of the PLL. Refer to the the
TLV320AIC33 datasheet for an explanation of
these parameters. The parameters can be set by clicking on the up/down arrows of the P, K, and R
combo boxes, or they can be typed into these boxes. The values can also be calculated by the PC
software.
To use the PC software to find the ideal values of P, K, and R for a given PLL input frequency and desired
Fsref, the desired Fsref must be set using the switch on this tab; it can be set to either 44.1kHz or 48kHz.
Once the desired Fsref and PLLCLK_IN values are correctly set, pushing the Search for Ideal Settings
button starts the software searching for ideal combinations of P, K, and R which achieve the desired Fsref.
The possible settings for these parameters are displayed in the spreadsheet-like table labeled Possible
Settings. Clicking on a row in this table sets the P, K, and R values in the software and updates the
PLL_OUT and PLLDIV_OUT readings, as well as the Actual Fsref and Error displays. This process does
not actually load the values into the TLV320AIC33, however; it only updates the displays in the software.
This allows for different possible solutions to be selected and the error evaluated before loading into the
device.
When a suitable combination of P,K, and R have been chosen, pressing the Load Settings into Device?
button will download these values into the appropriate registers on the TLV320AIC33.
The GPIO tab (see Figure 10 ) selects options for the general-purpose inputs and outputs (GPIO) of the
TLV320AIC33. Many pins on the TLV320AIC33 are denoted as multifunction pins, meaning they may be
used for many different purposes.
SBAU114 – November 2005 TLV320AIC33EVM and TLV320AIC33EVM-PDK User's Guide 19