ES_SMPREG_TRUNC_N
es1371_src_write(es, ES_SMPREG_DAC1 + ES_SMPREG_TRUNC_N, 16 << 4);
es1371_src_write(es, ES_SMPREG_DAC2 + ES_SMPREG_TRUNC_N, 16 << 4);
es1371_src_write(es, ES_SMPREG_ADC + ES_SMPREG_TRUNC_N,
es1371_src_write(es, ES_SMPREG_ADC + ES_SMPREG_TRUNC_N,