MII_DOUT
unsigned csr = TULIP_CSR_READ(sc, csr_srom_mii) & (MII_RD|MII_DOUT|MII_CLK);
unsigned lastbit = (csr & MII_DOUT) ? msb : 0;
csr ^= MII_DOUT; MII_EMIT; /* clock low; invert data */
unsigned csr = TULIP_CSR_READ(sc, csr_srom_mii) & (MII_RD|MII_DOUT|MII_CLK);
csr |= MII_DOUT; MII_EMIT; /* clock low; change data */
csr ^= MII_DOUT; MII_EMIT; /* clock low; change data */
unsigned csr = TULIP_CSR_READ(sc, csr_srom_mii) & (MII_RD|MII_DOUT|MII_CLK);
unsigned csr = TULIP_CSR_READ(sc, csr_srom_mii) & (MII_RD|MII_DOUT|MII_CLK);
unsigned csr = TULIP_CSR_READ(sc, csr_srom_mii) & (MII_RD|MII_DOUT|MII_CLK);