SDHC_PROT_CTRL
wrk32 = RD4(sc, SDHC_PROT_CTRL);
val32 = RD4(sc, SDHC_PROT_CTRL);
WR4(sc, SDHC_PROT_CTRL, val32);
protctl = RD4(sc, SDHC_PROT_CTRL);
WR4(sc, SDHC_PROT_CTRL, protctl);