menu "I2S PDM Example Configuration" choice EXAMPLE_PDM_DIR prompt "I2S PDM direction" default EXAMPLE_PDM_TX help Select example PDM direction config EXAMPLE_PDM_TX bool "PDM TX" depends on SOC_I2S_SUPPORTS_PDM_TX help PDM TX example will play 'twinkle twinkle little star' in three tones. config EXAMPLE_PDM_RX bool "PDM RX" depends on SOC_I2S_SUPPORTS_PDM_RX help PDM RX example will show the received data from a PDM microphone. endchoice choice EXAMPLE_PDM_TX_LINE_MODE prompt "I2S PDM TX Line Mode" depends on EXAMPLE_PDM_TX && SOC_I2S_HW_VERSION_2 default EXAMPLE_PDM_TX_CODEC help Decide to output PDM signal into a PDM codec or a low-pass filter config EXAMPLE_PDM_TX_CODEC bool "Codec line mode" help Output PDM signal to a PDM codec. The PDM clock signal is mandatory for PDM codec, the codec can differentiate the left and right sound channels by sampling data on positive or negative edges. That means the data of the left and right channels can coexist on a same data line. config EXAMPLE_PDM_TX_DAC bool "DAC line mode" help Output PDM signal to a low-pass filter, so that the low-pass filter can restore the PDM signal to analog wave. Therefore, each data line can only contains one sound channel, if both left and right channels are required, two data lines should be specified as well. Normally the PDM signal is not sufficient in DAC line mode. endchoice endmenu