NI6527_FILT_ENA_REG
writeb(val & 0xff, dev->mmio + NI6527_FILT_ENA_REG(0));
writeb((val >> 8) & 0xff, dev->mmio + NI6527_FILT_ENA_REG(1));
writeb((val >> 16) & 0xff, dev->mmio + NI6527_FILT_ENA_REG(2));