FE_FILTER_LEN
memset(af, 0, FE_FILTER_LEN);
memset(af, 0xff, FE_FILTER_LEN);
bus_space_write_region_1(bst, bsh, FE_MAR8, sc->filter, FE_FILTER_LEN);
uint8_t filter[FE_FILTER_LEN]; /* new filter value. */