VR_CR1
CSR_WRITE_1(sc, VR_CR1, VR_CR1_FULLDUPLEX | VR_CR1_TX_NOPOLL);
cr1 = CSR_READ_1(sc, VR_CR1);
CSR_WRITE_1(sc, VR_CR1, cr1);
CSR_WRITE_1(sc, VR_CR1, VR_CR1_RESET);
if (!(CSR_READ_1(sc, VR_CR1) & VR_CR1_RESET))