IPCC_SIGNAL_ID_MASK
signal_id = __SHIFTOUT(reg, IPCC_SIGNAL_ID_MASK);
__SHIFTIN(ih->ih_signal_id, IPCC_SIGNAL_ID_MASK));
__SHIFTIN(ih->ih_signal_id, IPCC_SIGNAL_ID_MASK));
__SHIFTIN(ch->ch_signal_id, IPCC_SIGNAL_ID_MASK));