Да, верно. Почему перебор? Есть какое-то ограничение?
У мена цап 8-канальный , у него 8 слотов по 32 такта на слот.
https://docs.espressif.com/projects/esp-idf/en/v5.4.1/esp32s3/api-reference/peripherals/i2s.html#tdm-mode
TDM Mode
TDM (Time Division Multiplexing) mode supports up to 16 slots. These slots can be enabled by i2s_tdm_slot_config_t::slot_mask.
But due to the hardware limitation, only up to 4 slots are supported while the slot is set to 32 bit-width, and 8 slots for 16 bit-width, 16 slots for 8 bit-width. The slot communication format of TDM is almost the same as the standard mode, yet with some small differences.