6.1 Configuring the Audio Serial Bus for the I
2
S Output
The PCMx120-Q1 features a highly flexible audio serial bus that can be configured to implement a wide range of
data formats. The default format is TDM, however the GUI can be used to change the data format to I
2
S. This
section describes how to configure the PCMx120-Q1 EVM for a 2-channel I
2
S output to a USB audio at 16 bits
and 48 kHz. Configure the AC-MB for USB audio as described in
. As shown in
audio serial bus tab.
Figure 6-6. Audio Serial Bus Tab
In the ASI format configuration pane (shown in
), change the protocol format to I
2
S, and the word
length to 16 bits.
Figure 6-7. ASI Format Configuration
When the protocol format is changed to I
2
S in the GUI, the USB audio processor on the AC-MB also changes
the audio format to I
2
S. The GUI reads the ASI status register (page 0 register 0x15), providing the detected
sampling rate and BCLK and FSYNC ratio. The ASI status register can also be read manually in the audio serial
bus tab by clicking the
Read
Figure 6-8. Clock Monitor Pane
Quick Start
18
ADCx120Q1EVM-PDK, PCMD3140Q1EVM-PDK Evaluation Module
Copyright © 2022 Texas Instruments Incorporated
