SDHC_DATA
*(u_int32_t *)datap = HREAD4(hp, SDHC_DATA);
u_int32_t rv = HREAD4(hp, SDHC_DATA);
HWRITE4(hp, SDHC_DATA, *((u_int32_t *)datap));
HWRITE4(hp, SDHC_DATA, rv);