get_tdm_channel_bck
tdm_con |= get_tdm_channel_bck(format) << CHANNEL_BCK_CYCLES_SFT;
tdm_con |= get_tdm_channel_bck(format) << CHANNEL_BCK_CYCLES_SFT;
tdm_con |= get_tdm_channel_bck(format) << CHANNEL_BCK_CYCLES_SFT;