STIC_XCOMM_SIZE
si->si_buf_phys + STIC_XCOMM_SIZE;
off = si->si_pbuf_select + STIC_XCOMM_SIZE;
sxi->sxi_buf_pktoff = STIC_XCOMM_SIZE;
STIC_XCOMM_SIZE + STIC_PACKET_SIZE * PX_BUF_COUNT;
(STIC_PACKET_SIZE * PX_BUF_COUNT + STIC_IMGBUF_SIZE*2 + STIC_XCOMM_SIZE)
off = si->si_pbuf_select + STIC_XCOMM_SIZE;
sxi->sxi_buf_pktoff = STIC_XCOMM_SIZE;
sxi->sxi_buf_imgoff = STIC_XCOMM_SIZE + STIC_PACKET_SIZE * 2;