sis_ctl
ld->sis_tx_list[i].sis_ctl = 0;
ld->sis_rx_list[i].sis_ctl = 0;
c->sis_ctl = htole32(ETHER_MAX_DIX_LEN);
ctl = letoh32(cur_tx->sis_ctl);
f->sis_ctl = htole32(SIS_CMDSTS_MORE | map->dm_segs[i].ds_len);
f->sis_ctl |= htole32(SIS_CMDSTS_OWN);
sc->sis_ldata->sis_tx_list[cur].sis_ctl &= ~htole32(SIS_CMDSTS_MORE);
sc->sis_ldata->sis_tx_list[*txidx].sis_ctl |= htole32(SIS_CMDSTS_OWN);
#define SIS_LASTDESC(x) (!(letoh32((x)->sis_ctl) & SIS_CMDSTS_MORE)))
#define SIS_OWNDESC(x) (letoh32((x)->sis_ctl) & SIS_CMDSTS_OWN)
#define SIS_RXBYTES(x) (letoh32((x)->sis_ctl) & SIS_CMDSTS_BUFLEN)