MAC_PPSx_TTNSR
tnsec = XGMAC_IOREAD(pdata, MAC_PPSx_TTNSR(index));
if (XGMAC_GET_BITS(tnsec, MAC_PPSx_TTNSR, TRGTBUSY0))
XGMAC_IOWRITE(pdata, MAC_PPSx_TTNSR(index), cfg->start.tv_nsec);