XMAC_CTRL_REG_RX_EN
val |= (XMAC_CTRL_REG_TX_EN | XMAC_CTRL_REG_RX_EN);
val &= ~(XMAC_CTRL_REG_TX_EN | XMAC_CTRL_REG_RX_EN);
val = XMAC_CTRL_REG_TX_EN | XMAC_CTRL_REG_RX_EN;