mkclock_isa_nvrd
ocsr = mkclock_isa_nvrd(sc, MK48T18_CLKOFF + MK48TXX_ICSR);
if (mkclock_isa_nvrd(sc, MK48T18_CLKOFF + MK48TXX_ICSR) != csr)
t1 = bcdtobin(mkclock_isa_nvrd(sc, MK48T18_CLKOFF + MK48TXX_ISEC));
t2 = bcdtobin(mkclock_isa_nvrd(sc, MK48T18_CLKOFF + MK48TXX_ISEC));
sc->sc_nvrd = mkclock_isa_nvrd;
uint8_t mkclock_isa_nvrd(struct mk48txx_softc *, int);