SL811_CSOF
if (sl11read(sc, SL811_CSOF) <= (uint8_t)pl)
remaining_bustime = (int)(slhci_read(sc, SL811_CSOF)) << 6;
slhci_write(sc, SL811_CSOF, pol|SL811_CSOF_MASTER|0x2e);
r = slhci_read(ssc, SL811_CSOF);