BITS_PER_SLOT
i2s_right_slot = (frame_len / 2) / BITS_PER_SLOT;
i2s_right_pause_interval = (frame_len / 2) % BITS_PER_SLOT;
i2s_right_pause_pos = i2s_right_slot * BITS_PER_SLOT;
reg1.r.rx_frm_len = frame_len / BITS_PER_SLOT - 1;
reg1.r.rx_sa_size = (sample_size / BITS_PER_SLOT) - 1;