MACCtrl0
iowrite16(ioread16(ioaddr + MACCtrl0) | EnbFlowCtrl,
ioaddr + MACCtrl0);
ioread32(ioaddr + MACCtrl0),
ioread16(ioaddr + MACCtrl1), ioread16(ioaddr + MACCtrl0));
iowrite16 (ioread16 (ioaddr + MACCtrl0) | EnbFullDuplex,
ioaddr + MACCtrl0);
iowrite16(ioread16(ioaddr + MACCtrl0) | (duplex ? 0x20 : 0), ioaddr + MACCtrl0);