PERIPH_CAP_CMD16
periph->periph_cap |= PERIPH_CAP_CMD16;
periph->periph_cap |= PERIPH_CAP_CMD16;
periph->periph_cap |= PERIPH_CAP_CMD16;
xs->cmdlen = (periph->periph_cap & PERIPH_CAP_CMD16) ? 16 : 12;
periph->periph_cap |= PERIPH_CAP_CMD16;