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6.9
Clocks Tab
Kit Operation
The TLV320AIC33 has a very flexible scheme for generating the clock sources for ADC and DAC sample
rates. The Clocks tab allows access to set the different options for setting up these clocks. Refer to the
Audio Clock Generation Processing figure in the
datasheet.
For use with the PC software and the USB-MODEVM, the clock settings must be set a certain way. These
settings are not the default settings of the TLV320AIC33. The EVM-required settings can be loaded
automatically by pushing the Load EVM Clock Settings button at the bottom of this tab. Note that
changing any of the clock settings from the values loaded when this button is pushed may result in the
EVM not working properly with the PC software or USB interface. If an external audio bus is used (audio
not driven over the USB bus), then settings may be changed to any valid combination. See
Figure 9. Clocks Tab
The codec clock source is chosen by by the CODEC_CLK Source control. When this control is set to
CLKDIV_OUT, the PLL is not used; when set to PLLDIV_OUT, the PLL is used to generate the clocks.
6.9.1
Use Without PLL
Setting up the TLV320AIC33 for clocking without using the PLL is straightforward. The CLKDIV_IN source
can be selected as either MCLK or BCLK, the default is MCLK. The CLKDIV_IN frequency is then entered
into the CLKDIV_IN box, in megahertz (MHz). The default value shown, 11.2896MHz, is the frequency
used on the USB-MODEVM board. This value is then divided by the value of Q, which can be set from 2
to 17; the resulting CLKDIV_OUT frequency is shown in the indicator next to the Q control.
TLV320AIC33EVM and TLV320AIC33EVM-PDK User's Guide
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SBAU114 – November 2005