uint8_t dac_loop(void) {
    uint8_t res = RET_OK;
    if((DMA1->HISR & DMA_HISR_HTIF5) && loop_go) {
        res = fsm_read_file(current_file, &dac_buff[0], 256);
        DMA1->HIFCR |= DMA_HIFCR_CHTIF5;
        if(res == RET_FILE_FINISHED) {
            return RET_FILE_FINISHED;
        }
    }
    if((DMA1->HISR & DMA_HISR_TCIF5) && loop_go) {
        res = fsm_read_file(current_file, &dac_buff[256], 256);
        DMA1->HIFCR |= DMA_HIFCR_CTCIF5;
        if(res == RET_FILE_FINISHED) {
            return RET_FILE_FINISHED;
        }
    }
    return RET_OK;
}