CTL0_START
l->ctl0 = CTL0_TXON | CTL0_RXON | CTL0_START;
CSR_WRITE_1(l, VR_CTL0, CTL0_START);
CSR_WRITE_1(l, VR_CTL0, CTL0_TXON | CTL0_RXON | CTL0_START);